Roxborough State Park

Background | Criteria | Northwest Colorado | Northeast Colorado
Southwest Colorado | Southeast Colorado

Roxborough State Park
Douglas County

Size: 3,299 acres

Elevation: 5900 - 7200 feet

Habitats: Primary – mountain shrubland

Secondary – aspen, cliff/rock, grassland, lowland riparian, mixed conifer, ponderosa pine, spruce/fir, wetlands

Ownership: State (CO State Parks)

Land Use: Primary – nature and wildlife conservation, undeveloped, nature education/interpretation

Secondary – recreation/tourism, research

IBA Criteria: 2, 5

Site description

Location: Located on the edge of the Rocky Mountain foothills in the Chatfield Basin, Roxborough State Park is 15 miles southwest of the Denver metro area.

Vegetative/natural features: The site’s geological features include sandstone spires and steep, colorful hogback formations. Its scrub oak/mountain mahogany shrubland and mid- to tall-grass prairie habitats support a wide diversity of animals, including over 157 species of birds. The site is located near the northern-most edge of the scrub oak shrubland habitat.

Ornithological Importance

At least 157 species of birds have been observed at the site. Park boundaries encompass part of the Dakota hogback, the whole of which is a known raptor migration route for 17 species of raptors and over 7,000 individuals annually. This same hogback also includes the Hawk Watch site within the Dinosaur Ridge IBA.

Breeding species:	Average #	Maximum #
Prairie Falcon	10	15
Common Poorwill	4 pairs
MacGillivray’s Warbler	2	4
Western Tanager	15 pairs
Canyon Wren	6 pairs	18
Cooper’s Hawk	4	8
Golden-winged Warbler	1	2
Lazuli Bunting	4	8

Migrant species:	Average #	Maximum #
Bald Eagle	2 (spring)	5 (spring)
Ferruginous Hawk	15 (spring)	20 (spring)
Northern Harrier	15 (spring, fall)	20 (spring, fall)
Prairie Falcon	10 (spring, fall)	15 (spring, fall)
Swainson’s Hawk	5 (spring, fall)	10 (spring, fall)
Cordilleran Flycatcher	2 (spring)	4 (spring)
Virginia’s Warbler	15 (spring, fall)	50 (spring, fall)
Western Tanager	15 pairs (spring, fall)
Canyon Wren	6 pairs (spring, fall)	18 (spring, fall)
Osprey	1 (spring)	1 (spring)
Turkey Vulture	~20 (spring, fall)	~30 (spring, fall)
Cooper’s Hawk	4 (spring, fall)	8 (spring, fall)
Peregrine Falcon	1 (spring)	1 (spring)

Wintering species:	Average #	Maximum #
Bald Eagle	2	5
Ferruginous Hawk	15	20
Northern Harrier	15	20
Prairie Falcon	10	15
Canyon Wren	6 pairs	18
Cooper’s Hawk	4	8

Research and educational activities: The site hosts numerous bird education and monitoring programs, including three guided bird hikes per month and International Migratory Bird Day. These programs reached 600 participants in 1999.

Conservation/Management Issues

Serious threats:
1. invasive/non-native plants (Canada thistle, yellow toadflax, diffuse knapweed);
2. habitat conversion and development of surrounding area.

Minor threats:
1. cowbird parasitism.

Potential threats:
1. introduced animals (house cats, starlings);
2. disturbance to birds and habitat;
3. trail construction and use.

Efforts to address threats:
Park managers are using an integrated weed management plan combining hand pulling and biological, chemical, and mechanical controls. To combat habitat conversion and development in surrounding areas, the Friends of Roxborough target visually and ecologically important land along park borders for purchase and preservation.

Management details:
Roxborough State Park is a Colorado Natural Area (based on rich diversity of habitats), a National Natural Landmark (based on unique geological formations), and a Colorado Watchable Wildlife site. Regulations do not permit pets, mountain biking, or rock climbing in the park.