November Nature Almanac: Threatened Canyons Shelter Autumn Treasures
By Stephen Jones and Ruth Carol Cushman
November 2024
[Updated 4 December 2024; see note at end]
In late October, we took a stroll down Forsythe Canyon, one of several forested drainages just west of Gross Reservoir. The canyon floor glowed with fall color: golden leaves of aspen and box elder, fiery wild rose, clumps of tender blue spruce needles scattered on the ground beneath pine squirrel nest trees.
Dogbane and box elder, along with aspen leaves, turn fiery yellow in late October. Photo by Stephen Jones.
Bronze Douglas-fir cones and blond-blue spruce cones piled up beneath the largest conifers, where the foraging squirrels chattered and fussed. Crumbling ponderosa pine logs on either side of the trail revealed where hungry black bears had torn open the decaying bark as they searched for grubs.
Soft young blue spruce boughs contrast with the red understory. Photo by Stephen Jones.
Farther down the canyon, a pair of Townsend’s Solitaires whistled and warbled while splashing in a shallow pool at the base of a polished granite cliff. Flocks of Dark-eyed Juncos, nuthatches, and Pine Siskins chattered in the tree canopy, while a family of American Robins fluttered from one fruit-laden juniper branch to another.
Trumpet gilia (Ipomopsis aggregate) was one of a dozen native wildflowers blooming on sunny hillsides in late October. Photo by Stephen Jones.
Blooming on sun-warmed hillsides were a dozen native wildflowers, including trumpet gilia (Ipomopsis aggregata), lemon-yellow evening-primrose (Oenothera biennis), and purple false aster (Virgulus sp.). We exulted in discovering that even on the cusp of November, these remote foothills canyons remain full of color and light.
Along the trail, garish blue and magenta numbers spray-painted on the bark of giant Colorado blue spruces, Douglas-firs, and ponderosa pines revealed a different story. This precious canyon and several others just west of Gross Reservoir are slated to be underwater when the Denver Water Board completes their 125-foot-high expansion of the reservoir dam. The blaze markings halfway down the canyon may indicate which trees will be cut down and which ones retained as the water rises to engulf them.
Garish blaze marks on some of the largest conifers indicate the level to which the reservoir water will rise if the project is eventually permitted to continue. Photo by Stephen Jones.
The pathway toward the reservoir expansion was made smoother a dozen years ago when the City of Boulder, which derives close to 30% of its water from the Colorado River and stores it in Boulder Reservoir, agreed not to oppose the Gross Reservoir dam expansion so long as Denver Water would raise the dam an additional 4ft. to accommodate some of Boulder’s Colorado River-sourced water. Ironically, City of Boulder planners spoke of using some of this water to establish minimum stream flows in South Boulder Creek, below the dam. [note: this paragraph was updated 4 December].
This 30-foot-high waterfall was just a trickle in late October, but the smooth, polished granite near the top indicates it supports a vigorous flow in late spring and early summer. Photo by Stephen Jones.
On October 16, 2024, a federal district court judge halted the project on the grounds that the U.S. Army Corps of Engineers had violated multiple federal laws when it issued a permit allowing Denver Water to expand the reservoir. Judge Christine M. Arguello determined that the Corps violated both the Clean Water Act and the National Environmental Policy Act when it issued a “dredge-and-fill” permit for Denver Water in 2017. She also noted that given the reality of global climate change, there may never be enough water available to fill the expanded reservoir.
The judge ordered Denver Water and the Army Corps of Engineers to begin meeting immediately with environmental groups to explore solutions. Gary Wockner of Save the Colorado said, “That conversation will start next week about how you actually remedy the extraordinary damage that’s been done in Boulder County, and then what to do next.”
We will be thinking lovingly of the squirrels, bears, solitaires, and fiery autumn foliage as this process plays itself out.
Thanks to Randy Gietzen and Cathern Smith for their field contributions to this article.
Wild rose turns vibrant pink and red in fall, and its fruits support foraging bears and birds. Photo by Stephen Jones.
Other November Events
Mule and white-tailed deer spar and mate.
Black bears typically go into hibernation, but if temperatures stay as warm as they’ve been so far this fall, many may wait until December.
Ducks put on their finest nuptial plumage.
Look for migrating loons and tundra swans at Baseline Reservoir, Lagerman Reservoir, and Union Reservoir.
Editor’s Note: On December 2, 2024, Aisha Ozaslan, Communications Senior Program Manager with the City of Boulder, sent an email to Boulder County Audubon requesting corrections to the original article. The author has re-written the two sentences in question based on his involvement with the approval process. This is reflected in the paragraph with the December 4th note above. The information provided by the City of Boulder on December 2nd is as follows:
The facts are that:
The City of Boulder does not currently store water in Gross Reservoir.
Boulder will store water in Gross Reservoir in the future, but it will not be Colorado River water.
Boulder did not condition its approval on getting storage space in the reservoir.
Boulder may have stated that “we do not oppose” the project, but we never actively took a position for or against the project.