M.4.2.7 Big Dominguez Canyon ACEC

Status: BLM proposed

General Location: Big Dominguez Creek is located on the eastern slope of the Uncompahgre Plateau and is the first major drainage southeast of Unaweep Canyon (Figure M.9).

Acreage: 5,626 acres

Significance: This site supports a good (B-ranked) occurrence of Colorado hookless cactus, a plant that is globally imperiled (G2G3/S2S3), and an excellent (A-ranked) example of Grand Junction milkvetch, a globally vulnerable (G3Q/S3) plant. The Grand Junction milkvetch is confined to the eastern base of the Uncompahgre Plateau in Mesa, Montrose, and Delta counties.

The State imperiled (G5/S2) and BLM sensitive canyon tree frog is also found here. The canyon tree frog inhabits rocky canyons along intermittent or permanent streams. This desert frog reaches its northern limits in Southern Colorado. Although primarily terrestrial, it breeds in canyon bottom pools surrounded by rock. It is usually found near permanent pools or cottonwoods in the pinyon-juniper zone. Desert bighorn sheep and peregrine falcon, both BLM sensitive species, frequent the canyon as well.

Biodiversity Significance: B2 or Very High

General Description: Dominguez Creek supports excellent riparian vegetation with a diversity of plant species, vigorous growth of vegetation, low abundance of non-native aggressive species, and diversity of vegetation structure. In a stretch of about sixteen air miles from Carson Hole on the Uncompahgre Plateau to the Gunnison River, this beautiful stream descends from 9,000 to 4,800 ft., transitioning from coniferous forests to desert shrubs and cactus.

Near the headwaters, mountain willow (Salix monticola) is common along the stream banks. Downstream, in the area of Big Dominguez Campground, the rushing stream forms small waterfalls and trout-filled plunge pools in the Precambrian rock. Riparian vegetation along this middle reach is very lush and diverse. Woolly sedge (Carex pellita), cloaked bulrush (Scirpus pallidus), Baltic rush (Juncus balticus), redtop (Agrostis gigantea), fowl mannagrass (Glyceria striata), horsetail (Equisetum arvense), scouring rush (Hippochaete laevigata), wild licorice (Glycyrrhiza lepidota), false-Solomon's seal (Maianthemum stellata), and canyon bog orchid (Limnorchis ensifolia) line the banks, while blue spruce (Picea pungens) and narrowleaf cottonwood (Populus angustifolia) tower above thickets of river birch (Betula occidentalis), thinleaf alder (Alnus incana), coyote willow (Salix exigua), and red-osier dogwood (Cornus sericea).

Approximately one to two miles downstream of the campground, beaver ponds have formed an extensive wetland complex consisting of open still water, scrub-shrub, and emergent wetlands. Above the creek, on the canyonsides, the bright green of pinyon-juniper contrast with red sandstone cliffs. Farther downstream, Plains cottonwood replaces the narrowleaf, as the canyon bottom winds below sheer Wingate sandstone cliffs. Two rare plants are found above the creek: Grand Junction milkvetch grows on rocky slopes and in ephemeral drainages in the pinyon-juniper zone, while Colorado hookless cactus is found in the lower reaches of the canyon in desert shrub communities.

Soils along Big Dominguez Creek are alluvium and generally not mapped on the County soil survey. The Glenberg series, coarse-loamy, mixed (calcareous), mesic, Ustic Torrifluvents, is shown to occur on floodplain terraces within the site (Soil Conservation Service 1978).

Values Assessed: Rare plants, Vegetation, Special Status Wildlife, and Cultural.

Relevance Criteria Considered: 3, 3, 2, 1

Importance Criteria Considered: 1,2 & 3, 2, 2, 1 & 2

Relevance Criterion		Yes/ No	Rationale for Determination
#	Description
3	A natural process or system (including but not limited to endangered, sensitive, or threatened plant species; rare, endemic, or relic plants or plant communities that are terrestrial, aquatic, or riparian; or rare geological features).	Yes	The ACEC includes occurrences of the Colorado hookless cactus and Grand Junction milkvetch.
3	A natural process or system (including but not limited to endangered, sensitive, or threatened plant species; rare, endemic, or relic plants or plant communities that are terrestrial, aquatic, or riparian; or rare geological features).	Yes	The excellent condition of riparian vegetation within the canyon is rare within the State of Colorado.
2	A fish and wildlife resource (including but not limited to habitat for endangered, sensitive, or threatened species or habitat essential for maintaining species diversity).	Yes	Special status wildlife known to use the ACEC include: Desert bighorn sheep Bald eagle Peregrine falcon Canyon tree frog
1	A significant historic, cultural, or scenic value (including but not limited to rare or sensitive archeological resources and religious or cultural resources important to Native Americans).	Yes	The canyon bottoms of the Dominguez Canyon area have evidence of human activity dating back thousands of years. There are numerous well-preserved rock art sites that constitute one of the highest concentrations in the planning area. The known rock art sites cover a long period, with some that date from over 2,000 years ago to Ute rock art panels from approximately 100 years ago.
Importance Criterion		Yes/ No	Rationale for Determination
#	Description
1, 2 & 3	Has more than locally significant qualities that give it special worth, consequence, meaning, distinctiveness, or cause for concern, especially compared to any similar resource. Has qualities or circumstances that make it fragile, sensitive, rare, irreplaceable, exemplary, unique, endangered, threatened, or vulnerable to adverse change. Has been recognized as warranting protection to satisfy national priority concerns or to carry out the mandates of FLPMA.	Yes	Rare Plants: This site supports a good (B-ranked) occurrence of Colorado hookless cactus, a plant that is globally imperiled (G2G3/S2S3), and an excellent (A-ranked) example of Grand Junction milkvetch, a globally vulnerable (G3Q/S3) plant. The Grand Junction milkvetch is confined to the eastern base of the Uncompahgre Plateau in Mesa, Montrose, and Delta counties.
2	Has qualities or circumstances that make it fragile, sensitive, rare, irreplaceable, exemplary, unique, endangered, threatened, or vulnerable to adverse change.	Yes	Vegetative Community: There is an excellent (A-ranked) occurrence of the State rare (G4/S3) narrowleaf cottonwood / red-osier dogwood riparian forest.
2	Has qualities or circumstances that make it fragile, sensitive, rare, irreplaceable, exemplary, unique, endangered, threatened, or vulnerable to adverse change.	Yes	Wildlife: Special status wildlife known to use the ACEC include: Desert bighorn sheep Bald eagle Peregrine falcon Canyon tree frog The canyon tree frog in particular has been identified as a species of greatest conservation concern by the State of Colorado.
1 & 2	Has more than locally significant qualities that give it special worth, consequence, meaning, distinctiveness, or cause for concern, especially compared to any similar resource. Has qualities or circumstances that make it fragile, sensitive, rare, irreplaceable, exemplary, unique, endangered, threatened, or vulnerable to adverse change.	Yes	Cultural Resources: The canyon bottoms of the Dominguez Canyon area have evidence of human activity dating back thousands of years. There are numerous well-preserved rock art sites that constitute one of the highest concentrations in the planning area. The known rock art sites cover a long period, with some that date from over 2,000 years ago to Ute rock art panels from approximately 100 years ago. All of these cultural resources are sensitive, irreplaceable and exemplary.

Figure 1 Big Dominguez Canyon ACEC