1
Environmental Conservation Area #1
Common Name: Indian Peaks
Location (General): East of the Continental Divide, bounded
by the county line to the north and south, west of SH72 and SH7
Size: 112,344 acres
Life Zones: Upper Montane, Sub-alpine, Alpine.
Rationale and Background:
The largest of the Environmental Conservation Areas (ECAs) is centered on the Indian Peaks Wilderness
and Rocky Mountain National Park. At 112,344 acres, it represents just over 20% of Boulder County. It is
our connection to the Continental Divide, the spine of the Southern Rocky Mountains, and the greater
Rocky Mountain National Park ecosystem. It represents the most likely habitat for Lynx and Wolverine in
the county. This is the summer home of most of our elk herds and bighorn sheep. Old growth forests,
willow carrs, boreal toads, black swifts, twayblades, ice grass, and several species of moonwort are
present. For some animals, this is probably their population source area.
Conservation efforts in this area have focused on protecting key ecological components at the lower
edge of the ECA: montane parklands and habitat connectors to lower elevations. In the mid-1980s, Lee
and Virginia Evans donated a conservation easement on the 650-acre Arapaho Ranch, a montane
parkland with important wetlands, grasslands, and transitional elk range, to Colorado Open Lands. BCNA
worked with the City of Longmont and Rocky Mountain National Park to help secure greater protection
of the Copeland Willow Carr (at 77 acres, it is the largest montane willow carr in the Front Range). The
site became designated as a State Natural Area. Boulder County, City of Boulder, and GOCO funds were
used to acquire easements or fee title to much of Caribou Ranch, another significant montane parkland.
Near where the South St. Vrain Creek crosses the peak-to-Peak Highway, a group of property owners
(Benedict, Welch, Goodnow, McKenna, Schmoll, and others) have donated conservation easements to
the Nature Conservancy and Boulder County to protect this important parkland and habitat connectors
between the Indian Peaks, South St. Vrain, and Walker Mountain ECAs.
In the late 1980s, Boulder County Nature Association supported, both financially and with volunteers, a
study of the movements of the Winiger Ridge elk herd. One of the outcomes of the study was the
recognition of the importance of Reynolds Ranch and surrounding lands along Magnolia Road to animal
movement between Winiger Ridge and the Arapaho Ranch and Indian Peaks. Boulder County has
acquired Reynolds Ranch and some of the surrounding lands in part to better conserve this wildlife
movement corridor.
Caribou Flats and Park have long been recognized as significant sites for a number of rare plants and
butterflies. It also contains some large subalpine willow carrs. A cooperative management effort
between the US Forest Service City, the city of Boulder Utilities, and several recreation groups have
helped to reduce damage from off-road vehicles.
Naturalness: Largest roadless area in the county. Most is designated Wilderness Area. Contains
Copeland Willow Carr Natural Area.
Indian Peaks ECA location within Boulder County.
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Quality and Uniqueness: Largest quantity of old-growth forests. Tundra. Montane parklands. High
number of significant wetlands. Habitat for Greenback Cutthroat Trout. Summer Elk concentration
areas. Several Elk-calving areas. Important movement corridors for large-mammals in both east/west
and north/south directions.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 33
Rare Plant Areas: 61
High Biodiversity Areas: 30
Natural Areas (B1-B3): Yes
Natural Landmarks: Yes
USFS Designations Acres
Backcountry Recreation
13,552
Intermix
8,780
Dispersed Recreation
5,163
Wilderness
4,416
Forested Flora and Fauna Habitats
4,317
Backcountry Recreation-Motorized
3,482
Scenery
3,236
Developed Recreation Complexes
2,622
Special Interest Areas-Emphasizing Use or Interpretation
1,061
Ski-Based Resorts
386
Other Designations
City of Boulder Watershed
Wild Basin Area, Rocky Mountain National Park, National Park Service
Niwot Ridge, Long Term Ecological Research Station, CU Boulder
Peak-to-Peak Scenic and Historic Byway, State of Colorado, DOT
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #2
Common Name: North Saint Vrain
Location (General): West of the town of Lyons, south of the
Boulder County border, north of South St. Vrain Dr., east of SH7
Size (acres): 38,133acres
Life Zones: Lower Montane, Upper Montane, Sub-alpine.
Rationale and Background:
The largest foothills to montane ECAs are centered on the North St. Vrain and South St. Vrain
Canyons. This ECA represents some of the best roadless foothill habitat along the Front Range. This area
contains old-growth ponderosa pine forests, elk winter concentration areas, golden eagle nest sites, and
good habitat for mountain lion and black bear. The North St. Vrain is a bighorn sheep concentration
area, a designated Wild Trout Stream, and contains a sizeable population of the rare plant Larimer
aletes. This ECA also contains imperiled plant communities comprised of foothill grass and shrub species
that have been degraded over much of the West.
During the mid-1980s conservation efforts were focused on preserving this area from additional
degradation. A proposal to place a dam and reservoir along the North St. Vrain between North and
South Sheep Mountains spearheaded an effort, largely through the work of BCNA’s Mike Figgs, to
recognize the ecological importance of the canyon and to stop the potential of any new main stem dams
on the creek. Local citizens and conservation groups worked to conserve private lands within these
areas. The Nature Conservancy purchased Sheep Mountain Ranch, located in the heart of the North St.
Vrain Canyon, until federal funds were available as a Forest Service aquisition. The 700-acre Riverside
Ranch, located west of Coffintop Mountain, was deeded to Boulder County Open Space after the
property owner transferred the development rights to a more acceptable receiving area. The Boulder
County Land Trust was actively talking with a number of the large ranch owners in both of the canyons.
Boulder County has purchased Open Space and conservation easements on many of these lands.
Conservation easements were purchased on the Trevarton Ranch, located west of North Foothills
Highway, and the Lillian Trevarton Ranch east of Meeker Park. The final large county acquisitions were
the purchases of the Hall Ranch and Heil Valley Ranch. With these acquisitions, the lower portions of the
North St. Vrain and South St. Vrain ECAs have been conserved.
The update of the Arapaho and Roosevelt National Forest Plan helped increase the protection of these
areas. Much of the North St. Vrain ECA was designated as a Research Natural Area. This designation has
increased the level of conservation placed on the canyons of north-central Boulder County.
Naturalness: Largest foothills/montane roadless area in county.
Quality and Uniqueness: Largest stands of old-growth Ponderosa pine/Douglas fir. Golden Eagle nest
sites. Wild trout stream. Elk critical winter range, winter concentration areas and calving areas.
Bighorn Sheep concentration area. Area is considered good habitat for Mountain Lion and Black Bear
due to montane/foothills habitat, size and high degree of naturalness. Excellent riparian habitat
along North St. Vrain Creek. Important east/west large mammal movement corridor. Prairie Dog colony.
North Saint Vrain ECA location within Boulder County.
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Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 7
Rare Plant Areas: 14
High Biodiversity Areas (B1-B3): 4
Natural Areas: Yes
Natural Landmarks: Yes
USFS Designations Acres
Forested Flora and Fauna Habitats
11203
Core Habitat Area
5584
Research Natural Area
5277
Dispersed Recreation
3595
Intermix
2981
Scenery
2112
Core Habitat Area
733
Other Designations:
Button Rock Preserve and Ralph Price Reservoir, City of Longmont
Wild Trout Water, Colorado Parks and Wildlife
Year Established: 1995
Year Revised: 2013
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Environmental Conservation Area #3
Common Name: South Saint Vrain and Foothills
Location (General): West of N 51
st
St., south of South St. Vrain Dr.,
North of Lefthand Canyon Dr.
Size (acres): 25,929 acres
Life Zones: Plains, Lower Montane, Upper Montane.
Rationale and Background:
The largest foothills to montane ECAs are centered on the North St. Vrain and South St. Vrain
Canyons. This ECA represents some of the best roadless foothill habitat along the Front Range. This area
contains old-growth ponderosa pine forests, elk winter concentration areas, golden eagle nest sites, and
good habitat for mountain lion and black bear. This ECA contains imperiled plant communities
comprised of foothill grass and shrub species that have been degraded over much of the West. Local
citizens and conservation groups worked towards protection of private lands within this area. Boulder
County has acquired conservation easements and Open Space on this area which has increased the
conservation of its outstanding ecological values.
The update of the Arapaho and Roosevelt National Forest Plan helped increase the protection of these
areas. The Central Gulch portion of the South St. Vrain was designated as Core Area. This designation
has increased the level of conservation placed on the canyons of north-central Boulder County.
Naturalness: Roadless areas exist in Central Gulch and South St. Vrain Canyon.
Quality and Uniqueness: Elk critical winter range, winter concentration areas and calving areas. Golden
Eagle nest sites. Small areas of old-growth ponderosa pine/Douglas fir. Area is considered good habitat
for Mountain Lion and Black Bear due to montane/foothills habitat, size and high degree of naturalness.
Important east/west large-mammal movement corridor. Prairie Dog colony.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 16
Rare Plant Areas: 44
High Biodiversity Area (B1-B3)s: 6
Natural Areas: Yes
Natural Landmarks: Yes
South Saint Vrain and Foothills ECA
location within Boulder County.
2
USFS Designations Acres
Core Habitat Area
5397
Forested Flora and Fauna Habitats
3637
Scenery
2633
Dispersed Recreation
2347
Intermix
2297
Other Designations:
None
Year Established: 1995
Year Revised: 2013
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Environmental Conservation Area #4
Common Name: Walker Mountain
Location (General): West of James Canyon Dr., south of Jamestown,
North of Lefthand Canyon Dr., east of the town of Ward
Size (acres): 9234 acres
Life Zones: Lower Montane, Upper Montane, Sub-alpine.
Rationale and Background:
This ECA is located in the heart of Boulder County’s mineral belt, while having some fragmentation, it
contains significant ecological qualities along with geographic importance.
The Walker Mountain ECA is generally located south of Jamestown, north of Lefthand Canyon, east of
the intersections of James Canyon Dr. and Lefthand Canyon, and west of Ward. It contains several
roadless areas, stands of old growth ponderosa pine and Douglas-fir, an elk winter concentration area,
and a high quality riparian area along Spring Gulch. Local citizens have worked to conserve the water
quality of James Creek and the forest ecosystems surrounding it and to reduce fragmentation by closing
some roads to James Creek. These efforts have also worked to close social trails by unauthorized
motorized recreation in the Walker Mountain area. Several of the property owners south of Overland
Road and along the Peak-to-Peak Highway have donated conservation easements to The Nature
Conservancy. These easements protect an important animal movement corridor linking Walker
Mountain ECA to the Indian Peaks. Boulder County has acquired several inholdings within the ECA to
further reduce fragmentation.
Naturalness: Roadless areas exist on east flank of Nugget Hill, north flank of Walker Mountain and
between spring Gulch and Gold Lake.
Quality and Uniqueness: Elk critical range and winter concentration areas. Old-growth ponderosa
pine/Douglas fir. Spring Gulch is considered high quality riparian/wetland habitat. Important east/west
large-mammal movement corridor.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count Acres
Critical Wildlife Habitats: 0
Rare Plant Areas: 0
High Biodiversity Area (B1-B3)s: 3
Natural Areas: No
Natural Landmarks: No
Walker Mountain ECA location within Boulder County.
2
USFS Designations Acres
Forested Flora and Fauna Habitats
5440
Intermix
2292
Private
539
Dispersed Recreation
537
Intermix
5
Other Designations:
None
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #5
Common Name: Fourmile Creek and Bald Mountain
Location (General): West of Dixon Rd., south of Gold Hill Rd.,
north of Sugarloaf Rd., east of SH72
Size (acres): 8,451 acres
Life Zones: Lower Montane, Upper Montane, Sub-alpine.
Rationale and Background:
Three ecologically significant areas anchor Fourmile Creek/Bald Mountain ECA. Bald Mountain (the one
along the Switzerland Trail railroad grade road) is a Colorado Natural Heritage Program (CNHP) Element
Occurrence of Foothills Ponderosa Pine Savannah, as well as several other types of montane grassland.
Todd Gulch Fen, located along the Gold Hill Road, is a highly biodiverse area. The third area is a one mile
stretch of Fourmile Creek between Sunset and the Peak-to-Peak Highway that is roadless and trailess.
This ECA faces some challenges from unauthorized motorized recreation.
Naturalness: Roadless area exists along Fourmile Creek west of Sunset. Much of landscape, except for
Fourmile Canyon Road and Switzerland Trail, is steep and roadless.
Quality and Uniqueness: Elk critical winter range. Old-growth ponderosa pine, Douglas fir and
Lodgepole pine. Important east/west large-mammal movement corridor.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 1
Rare Plant Areas: 10
High Biodiversity Areas (B1-B3): 4
Natural Areas: No
Natural Landmarks: Yes
USFS Designations Acres
Dispersed Recreation
4663
Forested Flora and Fauna Habitats
2122
Scenery
557
Private
357
Intermix
489
Special Interest Areas-Emphasizing Use or
Interpretation
100
Fourmile Creek and Bald Mountain ECA
location within Boulder County.
2
Other Designations:
None
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #6
Common Name: Winiger Ridge
Location (General): West of Gross Res., south of Flagstaff Rd., north of
the Boulder County border, east of Magnolia Dr.
Size (acres): 3,460 acres
Life Zones: Lower Montane, Upper Montane.
Rationale and Background:
The Winiger Ridge ECA is an area which has received significant conservation and restoration. Winiger
Ridge has long been known as an important wintering area and movement corridor for elk. The area
contains two important Foothill Riparian areas along South Boulder Creek (above Gross Reservoir) and
Winiger Gulch, both recognized as highly biodiverse regions. The US Forest Service has been working to
control unauthorized motorized recreation.
Due to significant efforts by private citizens and the US Forest Service, the area between Winiger Gulch
and South Boulder Creek serves as an effective core preserve.
Naturalness: Roadless area in South Boulder Creek Canyon west of Gross Reservoir. Winiger Ridge is
closed to motorized vehicles during winter.
Quality and Uniqueness: Elk critical winter range and winter concentration area. Old-growth Ponderosa
pine/Douglas fir. Important east/west large-mammal movement corridor.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 1
Rare Plant Areas: 0
High Biodiversity Areas (B1-B3): 1
Natural Areas: No
Natural Landmarks: Yes
USFS Designations Acres
Forested Flora and Fauna Habitats
3425
Other Designations:
Year Established: 1995
Year Revised: 2013
Winiger Ridge ECA location within Boulder County.
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Environmental Conservation Area #7
Common Name: Hawkin Gulch/Walker Ranch/Upper Eldorado Canyon
Location (General): West of Eldorado Springs, south of Boulder
Canyon Dr., north of the Boulder County border, east of Gross Res.
Size (acres): 10,185 acres
Life Zones: Lower Montane, Upper Montane.
Rationale and Background:
This ECA acts to conserve critical resources in the south-central
part of the County. This area contains a multitude of significant plants, plant communities, and wildlife
and provides an important mountain to prairie link.
Walker Ranch is at the center of the Hawkin Gulch/Walker Ranch/Upper Eldorado Canyon ECA and
occurs within an area which initially acquired as Boulder County Open Space. It provides important
winter range for elk. The western portion of this ECA, centered on Twin Sisters, is a critical migration
corridor for elk and other large mammals; this site became an important habitat connector due to the
creation of Gross Reservoir in the 1950s, which is an effective barrier to east-west movement of animals
in this part of the county. The canyons and gulches between Flagstaff Drive, Boulder Canyon and
Magnolia Road, including Hawkin, Keystone, and Calhoun Gulches, are wild and rugged areas. Upper
Eldorado Canyon is another wild and rugged region. Ownership is mixed between Eldorado Canyon
State Park and Boulder County Open Space. Running through this area is South Boulder Creek. It is one
of the few roadless foothill creeks in the county, the others being Fourmile Canyon Creek and the North
St. Vrain Creek. All of the others, including Boulder Creek, Fourmile Creek (the Fourmile Creek that
heads to Sunset), Lefthand Creek, James Creek, and South St. Vrain Creek, are impacted by adjacent
roads.
Naturalness: Several roadless areas in Hawkin Gulch, south half of Walker Ranch, South Draw, Johnson
Gulch, Keystone Gulch and Twin Sisters Peak.
Quality and Uniqueness: Elk critical winter range and winter concentration area. Old-growth ponderosa
pine/Douglas fir. Area is considered good habitat for Mountain Lion and Black Bear due to foothills
habitat, size and high degree of naturalness. Important east/west and north/south large-mammal
movement corridor.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 4
Rare Plant Areas: 64
High Biodiversity Areas (B1-B3): 1
Natural Areas: Yes
Natural Landmarks: Yes
Hawkin Gulch/Walker Ranch/Upper Eldorado
Canyon ECA location within Boulder County.
2
USFS Designations Acres
Forested Flora and Fauna Habitats
2135
Intermix
73
Other Designations:
Eldorado Canyon State Park, State of Colorado
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #8
Common Name: Boulder Mountain Park and South Boulder
Location (General): West of McCaslin Blvd., south of US36, north of
the Boulder County border, east of Eldorado Springs
Size (acres): 19,443 acres
Life Zones: Plains, Lower Montane.
Rationale and Background:
This ECA acts to conserve critical resources in the south-central part of the County. It contains a
multitude of significant plants, plant communities, and wildlife and provides an important mountain to
prairie link.
The canyons and peaks of the Mountain Parks are very diverse floristically, harboring a number of rare
plants, including dwarf wild indigo, paper birch, Rocky Mountain sedge, broad-leafed twayblade, white
adder’s-mouth, pictureleaf wintergreen, and Weatherby’s spike-moss. Nesting sites of golden eagles,
prairie falcons, and peregrine falcons are present in the flatirons and canyons, as well as feeding
grounds on the grasslands to the east. These grasslands periodically contain one of the largest prairie
dog colonies in Boulder County. Ute ladies’tresses orchid and Preble’s meadow jumping mouse are
some of the significant biological elements present. Marshall Mesa, Eldorado Springs Canyon, and
Tallgrass Prairie are designated Natural Areas. This ECA is now adjacent to the 4,000-acre Rocky Flats
National Wildlife Refuge to the south. The city of Boulder has been working to protect lands in
neighboring Jefferson County and represents an important linkage across the county border.
Naturalness: Roadless areas exist within Boulder Mountain Parks, and Open Space areas north and
south of Eldorado Springs Road and east of S. Foothills Highway. Area is suitable for additional prairie
restoration. Region may present opportunities for reintroduction of extirpated species. Potential for
enhancing prairie dog community to replace winter raptor concentration areas located east of McCaslin
Blvd.
Quality and Uniqueness: High density of nesting raptors (Golden Eagles, Prairie Falcons, Peregrine
Falcon). High concentration of rare plants. Winter raptor concentration area. Good conditioned prairie
plant communities. Important east-west and north-south large-mammal movement corridor and elk
calving. Significant riparian community along South Boulder Creek and Coal Creek. Prairie Dog Colony.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Boulder Mountain Park and South Boulder ECA
location within Boulder County.
2
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 14
Rare Plant Areas: 17
High Biodiversity Area (B1-B3)s: 6
Natural Areas: No
Natural Landmarks: Yes
USFS Designations Acres
None
Other Designations:
Eldorado Canyon State Park, State of Colorado
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #9
Common Name: Rabbit Mountain
Location (General): West N 75
th
St., south of the
Boulder County border, north of SH66, east of the town of Lyons
Size (acres): 7831 acres
Life Zones: Plains, Lower Montane.
Rationale and Background:
This Environmental Conservation Area in the north-central portion of the county has been mostly
acquired as Boulder County Open Space or conversation easement. The purpose of these acquisitions
has been for the primary purpose of habitat conservation for the natural resources it contains. This area
represents one of the highest biodiversity regions in the county and exists in a relatively unfragmented
condition.
Rabbit Mountain is a unique eastward extension of the foothills. It contains several imperiled plant
communities that include ponderosa pine, mountain mahogany and several prairie grasses. It has a long-
established and successful Golden Eagle nesting territory and supports a highly diverse avian
community. A population of the rare Bell’s twinpod is found there. The ECA is a concentration area for
raptors during the winter due to the presence of prairie dogs on Dowe Flats and many other small
mammal species on Rabbit Mountain. Several herds of mule deer use the property, some for winter
range, as do white-tailed deer and occasionally elk.
Naturalness: Roadless areas exist on the existing Boulder County Open Space.
Quality and Uniqueness: Winter raptor concentration area. Significant Prairie dog colony. Golden eagle
nesting territory. Fair quality ponderosa pine/shrub/grass community. Large Bell's Twinpod community.
Good riparian habitat along Little Thompson River. Important east-west large-mammal movement
corridor.
Restoration Potential: Actions should be taken to increase the amount of restored prairie habitat and
to protect the significant shrub communities present in the area. All efforts to limit or reverse habitat
fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 1
Rare Plant Areas: 7
High Biodiversity Areas (B1-B3): 2
Natural Areas: Yes
Natural Landmarks: Yes
Rabbit Mountain ECA location within Boulder County.
2
USFS Designations Acres
None
Other Designations:
None
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #10
Common Name: Table Mountain
Location (General): West of N 55
th
St., south of Nelson Rd.,
north of Oxford Rd., east of N 41
st
St.
Size (acres): 1701 acres
Life Zones: Plains
Rationale and Background:
This ECA is located in the central portion of the county and aids in conserving important prairie,
wetlands, and habitat connectors linking the foothills to the plains.
The Table Mountain ECA is centered on a 1,700-acre tract of Federal land used as a radar and
communications facility. The overall lack of use has helped retain a large block of native midgrass
prairie. Boulder County Open Space and the City of Boulder have acquired adjacent and nearby lands
and easements in order to expand this ECA and build a habitat connector to the foothills.
Naturalness: Area has some service roads where access is controlled. Is not currently being grazed.
Quality and Uniqueness: Large block of native midgrass prairie.
Restoration Potential: Actions should be taken to retain the existing prairie habitat, as well as enhance
existing connectivity with the foothills ECAs. All efforts to limit or reverse habitat fragmentation should
be pursued.
Key Facts:
Boulder County Designations Count Acres
Critical Wildlife Habitats: 0
Rare Plant Areas: 0
High Biodiversity Areas (B1-B3): 1
Natural Areas: Yes
Natural Landmarks: Yes
USFS Designations Acres
None
Other Designations:
None
Year Established: 1995
Year Revised: 2013
Table Mountain ECA location within Boulder County.
1
Environmental Conservation Area #11
Common Name: Boulder Valley Ranch and Beech Open Space
Location (General): West of N 63
rd
St., south of Niwot Rd.,
North of Lee Hill Dr., east of Lefthand Canyon Dr.
Size (acres): 7,227 acres
Life Zones: Plains, Lower Montane.
Rationale and Background:
This ECA is located in the central portion of the county. The area acts to protect important prairie,
wetlands, and habitat connectors linking the foothills to the plains.
The Boulder Valley Ranch and Beech Open Space ECA is centered on the two open space properties
within its name. It also includes portions of Boulder Reservoir and numerous other open space
properties on the north flank of the City of Boulder. This is a winter raptor concentration area,
periodically containing a large prairie dog colony. A Northern Harrier nesting site is found within this
area. There are significant wetlands and several locations for the rare Bell’s twinpod. Northern harriers
have historically nested within this ECA, as have burrowing owls. The wetlands and deciduous forests
along the west and north sides of Boulder Reservoir are home to a number of rare and vulnerable
nesting birds. This ECA spans from the foothills to the plains and can be used as an animal movement
corridor. It also contains Six-Mile Fold Natural Area.
Naturalness: Roadless areas exist on Open Space properties. Prairie and wetland restoration potential.
Contains Six-Mile Fold Natural Area.
Quality and Uniqueness: Winter raptor concentration area. Significant Prairie dog colony. Significant
wetlands. Northern Harrier nesting area. Historic and potential nesting for Burrowing Owl. Several sites
for Bell's Twinpod. Important north/south and east/west large-mammal movement corridor.
Restoration Potential: Actions which enhance the function of habitats in this ECA should be a priority,
including conservation and preservation of wetlands and other highly-productive habitats which lead to
a functional prairie ecosystem. All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count Acres
Critical Wildlife Habitats: 7
Rare Plant Areas: 2
High Biodiversity Areas (B1-B3): 1
Natural Areas: Yes
Natural Landmarks: Yes
Boulder Valley Ranch and Beech Open Space
ECA location within Boulder County.
2
USFS Designations Acres
None
Other Designations:
None
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #12
Common Name: White Rocks and Gunbarrel Hill
Location (General): West of SH287, south of Niwot Rd.,
north of Valmont Rd., east of N 75
th
St.
Size (acres): 6,988 acres
Life Zones: Plains.
Rationale and Background:
This ECA along with the East County ECA work together to protect critical resources in the east part of
the County. Each contains a multitude of significant plants, plant communities, and wildlife. And
together they total 15,000 acres, providing an important movement corridor along Boulder Creek and
between Boulder and St. Vrain creeks.
The White Rocks/Gunbarrel Hill ECA spans west to east from N75th Street to Highway 287 and north to
south between Highway 52 and Valmont Road. The White Rocks and the riparian lands along Boulder
Creek form the heart of this area, as does Gunbarrel Hill, which was once a dryland farming area and is
now being restored to prairie. The White Rocks contains a number of imperiled plants and animals,
including rare ants and ferns. There is a high concentration of nesting raptors, good quality riparian
habitat and significant wetlands. Portions of Boulder Creek are being restored by the City of Boulder as
meanders are being put back into portions that were straightened. The area contains the White Rocks
State Natural Area and the Heron Rookery State Natural Area.
Naturalness: Roadless areas exist on Open Space and private inholdings. Gunbarrel Hill has good
potential for prairie restoration. Some of the land is currently in Federal Conservation Reserve Program.
Contains White Rocks Natural Area and Heron Rookery Natural Area.
Quality and Uniqueness: The “White Rocks". High concentration of rare plants and animals. High
concentration of nesting raptors. Good quality riparian habitat and significant wetlands. Some native
prairie. Boulder Creek is important wildlife movement corridor. Prairie Dog colonies.
Restoration Potential: This area has received extensive prairie restoration and has the potential to be a
large and functional native prairie habitat in the eastern section of the county. All efforts to limit or
reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 6
Rare Plant Areas: 1
High Biodiversity Areas (B1-B3): 1
Natural Areas: Yes
Natural Landmarks: No
White Rocks and Gunbarrel Hill ECA
location within Boulder County.
2
USFS Designations Acres
None
Other Designations:
None
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #13
Common Name: East County
Location (General): West of East County Line Rd., north of SH52,
south of SH119, east of SR287
Size (acres): 7,819 acres
Life Zones: Plains.
Rationale and Background:
This ECA along with the White Rocks and Gunbarrel Hill ECA work together to protect critical resources
in the east part of the County. Each contains a multitude of significant plants, plant communities, and
wildlife. And together they total 15,000 acres, providing an important movement corridor along Boulder
Creek and between Boulder and St. Vrain creeks.
The East County ECA spans north to south between St. Vrain and Boulder Creek, and west to east
between Highway 287 and the county line. Much of this area is irrigated farmland, which has been
acquired by the County as Open Space or conservation easement. The farmland provides a level of
seclusion necessary for several nesting raptors. Some of the ecological features of this ECA include
Boulder Creek, Panama Reservoir, Lefthand Creek, and St. Vrain Creek. Great blue herons have a small
rookery in this area. Restoration has occurred along some of the riparian corridors and continues to be a
conservation priority. The area provides a movement corridor for white-tailed deer between Boulder
and St. Vrain Creeks.
Naturalness: The Open Space and Conservation easements acquired by Boulder County have guided
land use within this ECA and retained many of the remaining natural features of this area.
Quality and Uniqueness: Reservoir and shoreline vegetation with Great Blue Heron nests. Bald Eagle
nesting and habitat. Good quality riparian area and wetlands along St. Vrain Creek and Boulder Creek.
Provides north/south wildlife movement corridor in the eastern side of Boulder County.
Restoration Potential: Restoration and conservation activity should be considered which promotes
prairie and riparian habitats, or which increases connectivity with the adjacent ECA and riparian
corridors. All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count Acres
Critical Wildlife Habitats: 3
Rare Plant Areas: 0
High Biodiversity Areas (B1-B3): 0
Natural Areas: No
Natural Landmarks: No
East County ECA location within Boulder County.
2
USFS Designations Acres
None
Other Designations:
None
Year Established: 1995
Year Revised: 2013
1
Environmental Conservation Area #14
Common Name: Magnolia
Location (General): East of Nederland, bounded on the north
by Boulder Canyon, west of Winiger Ridge and Gross Res.
Size (acres): 7,126 acres
Life Zones: Lower Montane, Upper Montane.
Rationale and Background:
The Magnolia ECA is an area which has received significant conservation and restoration by Boulder
County Parks and Open Space, the USFS, and others. It is relatively unfragmented by roads and
development. Additionally, this area has long been known as an important movement corridor for elk.
This area is also included in the planning area for the Magnolia Environmental Preservation Plan, which
seeks to protect the “unique rural qualities, unfragmented habitats, wildlife, scenic and recreational
resources” of the Magnolia area.
Naturalness: Relatively undeveloped and unfragmented area east of Barker Res. Much of the area is
public land (Boulder County Parks and Open Space, USFS, State of Colorado).
Quality and Uniqueness: High quality plant sites and plant diversity. Old-growth Ponderosa
pine/Douglas fir. Important east/west large-mammal movement corridor.
Restoration Potential: All efforts to limit or reverse habitat fragmentation should be pursued.
Key Facts:
Boulder County Designations Count
Critical Wildlife Habitats: 2
Rare Plant Areas: 26
High Biodiversity Areas (B1-B3): 0
Natural Areas: No
Natural Landmarks: Yes
USFS Designations Acres
Forested Flora and Fauna Habitats
5028
Intermix
1979
Other Designations:
Magnolia Environmental Preservation Plan
Year Established: NEW
Year Revised: 2013
Winiger Ridge ECA location within Boulder County.
