Heavy Snow Prompts Avalanches at T-Mountain Gulch, Slum Pass
Snow accumulation topping 24” of heavy, wet snow in high mountain areas near Lake City last Thursday and Friday, March 7 and 8, resulted in a succession of late winter snowslides, including a late evening slide March 8 on Slumgullion Pass which blocked both lanes of Highway 149.
Slides have also run on tributaries to Henson Creek in the vicinity of the Ute-Ulay Mine, one of the largest of which occurred early Saturday morning, March 9, as a mammoth wall of snow from 13,084’-elevation T-Mountain cascaded down T-Mountain Gulch.
Termed by long-time locals such as George Hurd the largest T-Mountain Gulch slide which they’ve ever seen, the slide came down the gulch with such fury that it completely denuded a ridge of spruce trees near the mouth of the gulch, inundated Henson
Creek and crossed to the opposite side of the canyon covering Hinsdale County Road to a depth of 10’ over a 100-yard stretch just below the Ute-Ulay Mine.
As an indication of the velocity of the avalanche, trees on the opposite side of the road had branches broken 40’ from the ground.
Saturday’s T-Mountain Gulch slide eerily mirrors an earlier slide on April 27, 2011, which followed an identical course down the gulch and briefly dammed water in Henson Creek. The 2011 slide was a precursor to mine tailings remediation work at the Ute-Ulay Mine, although in retrospect to this year’s slide was much smaller.
While blocking Henson Creek, the 2011 slide did not extend as far as Hinsdale County Road 20; by contrast, last Saturday’s early morning slide consisted of large expanses of fractured snow from above-timberline slopes of T-Mountain which in turn cascaded into numerous chutes leading into T-Mountain Gulch.
The cumulative impact overwhelmed the gulch and blasted over an acre-size, tree-covered ridge which had remained pristine in 2011. In 2019, however, the mammoth slide — actually two slides, an earlier, larger snowslide followed in short order by a second slide — sheered off every single tree on the ridge, leaving the slope completed denuded.
The slide crossed and filled Henson Creek Canyon with such power that it ripped out trees beside the creek which had survived the 2011 slide and then continued up the mountainside to inundate the county road.
Remnants of the 2011 slide remained into 2012, and it is likely that the icy mass of the 2019 T-Mountain Gulch slide will likewise remain throughout the coming summer and into 2020.
In the wake of avalanche warnings which remained at elevated levels leading up to closure of County Road 20 early this week, exploration of upper Henson Creek snowslides has necessarily been limited. The few who ventured further up canyon beyond T-Mountain Gulch last weekend report that another mammoth snowslide covers the Henson Creek Road above the Ute-Ulay adjacent to Modoc Creek.
Tom Carl and R.E. Hall ventured up to the Modoc Slide on Sunday and report that water was backed up behind the clogged river course; like the down- stream T-Mountain Gulch slide, the slide opposite Modoc Creek has uprooted entire trees, many sizeable and over 100 years old. The strength of the slide, Carl says, is evident by the trees’ root balls which were literally ripped out of the ground.
Up from Modoc Creek are a number of other well- known Henson Creek snowslides which are also near-certain to run this year, including established snow chutes at the Twins, Klondike, Big Casino, Copper Gulch and Lee Smelter Gulch which are located along the stretch of Henson Creek from the Ute-Ulay Mine up to Capitol City.
Closer to home, motorists on Slumgullion Pass were stranded for several hours Friday evening, March 8, as the result of a little known snowslide just below Windy Point, the “Turkey Foot” slide, which blocked both lanes on Highway 149.
According to R.E. Hall, TM-2 Lead Worker for Colorado Dept. of Transportation’s Lake City crew, the Turkey Foot slide is a near-annual occurrence on Slumgullion Pass but typically only covers a roadside pullout located at the base of a tree-covered bluff just below the popular Windy Point Overlook. On rare occasion, the Turkey Foot will cascade out onto the highway, perhaps blocking a single traffic lane. The last time the slide covered both lanes of the highway was around 2003.
Hall this year, however, terms the Turkey Foot a “big slide” which covered both lanes of the highway’s full width, 20’ deep and 100 to 125’ across.
With heavy snowfall totaling 24” of new snow on Thursday and Friday, CDOT workers put in a 14-hour day clearing snow while maintaining both Slumgullion and Spring Creek passes on Friday.
Lead Worker Hall reports that both of his CDOT colleagues on the Lake City crew, Joe Wonnacott and Randy Smart, both classified as TM-1 workers, were enlisted in the wake of the Turkey Foot slide, as well as aid which was provided by JoAllen Blowers and Don Menzies from Hinsdale County Road & Bridge.
Local CDOT worker Joe Wonnacott had a first hand view of the slide as he prepared to cease work on Slumgullion and was heading down to Lake City in the CDOT plow shortly after 6 p.m. Friday. Rounding a corner on the highway just below Windy Point, Wonnacott was surprised to encounter a wall of snow blocking the highway estimated at 20’ depth at centerline.
Wonnacott immediately radioed dispatch to alert both Hall and Smart, reporting that both he and motorists in two other vehicles were blocked on the uphill-side of the slide.
One of the passenger cars blocked by the snowslide was
Lake City bank employee
Cody Menzies whose father, Don Menzies, is Shop Foreman at Hinsdale County Road & Bridge.
With Wonnacott in the snowplow on the uphill side, and Hall, Smart and Blowers in front end loaders on the downhill side, the men worked for over three hours, until 9:45 p.m. Friday, opening a single lane through the slide. Mop-up work continued for another hour, until just past 10:30 p.m. before both lanes of the highway were reopened.
In addition to Don Menzies who provided traffic control, others assisting were Sheriff Justin Casey and members of his dept. who also checked for snowslide activity north of Lake City on snowslide-prone section of Highway 149 known as “North Canyon.” Gunnison CDOT Junior Foreman Justin Mangum also responded to the scene.
Questioned on mandatory avalanche training for CDOT workers, Hall says that he and members of the Lake City crew are annually required to enroll in avalanche training refresher courses which are usually held with other CDOT workers from the Wolf Creek region in South Fork, Colorado.
Lake City crew members stock beacons, shovels and probes among their standard winter equipment, the goal being, says Hall, to “keep everyone safe.”
Hall, joined by Mark Mueller, Lead Avalanche Forecaster out of Pagosa Springs with the Colorado Avalanche Center, was back on Slumgullion Pass on Saturday morning following the Friday evening slide. Mueller and Hall took statistics at the site in terms of the snowslide’s length and width, and observed the meandering trajectory of the Turkey Foot down the mountainside from its start to its collision across Highway 149. According to both Hall and Mueller, the Turkey Foot is somewhat unusual in the fact that it gathered volume and momentum in the midst of a tree-covered slope. For this reason, according to Mueller, advance mitigation of the slide would “not be manageable.”
After checking statistics, Mueller strapped on skis to record snow conditions in the hillside above where the slide started, as well as an adjacent unnamed snowslide which also slid on Friday, although it stopped several hundred yards above the highway.
According to Mueller, the explanation for the Turkey Foot slide, as with other slides in the region, was a poor snow foundation near its base. A thin layer of snow remained at ground level after the slide, the top 30” of the snowpack fracturing and creating the snowslide.
In addition to the Turkey Foot, R.E. Hall remarks on other challenges to keeping Highway 149 open to motorists on both Slumgullion and Spring Creek passes this winter. Drifting snow has been exacerbated at upper levels of Slum Pass as a result of the removal of beetle-killed spruce trees which formerly sheltered the highway.
Hall points to “bank slides” which occasionally occur on both passes, including several instances during last weekend’s snowfall. Bank slides are cut banks of snow on the right-of-way of the highway which due to snow accummulation and wind sometimes abruptly collapse. Bank slides seldom impact both lanes but have the potential to partially block one lane of the highway.
Last Friday evening several bank slides adjacent to the Turkey Foot slide collapsed, burying portions of the north-bound lane under 6’ to 8’ of snow. Bank slides also occurred near the pass summit and near the turnoff to the Deer Lakes and the Cathedral road.
Hall also says the state road crew is keeping up on slides which are occuring on Highway 149 to the north of Lake City in a section known as “North Canyon” extending roughly from Valley View Ranch to High Bridge.
Within that section, several slides have already occurred in what is termed the “Larson Creek Chutes,” the largest of which buried the highway 3 -1/2’-deep at centerline. Other slides are known to occur near the Lake Fork Bridge, cliffs near Independence Gulch, and near the Elk Meadows Bridge.
Hall notes that snowslide activity in the North Canyon section has become more prevalent in recent years and especially since heavy rains in August the past several years “scoured” the chutes. Without gravel and accumulated debris in the chutes, Hall surmises, it is easier for snowslides to descend and reach the highway.
Elsewhere in the Lake Fork Valley, snowslides are reported in the vicinity of Bucksnort/Hammond Meadow, including a snowslide which has reportedly blocked the access road to the LeGrand house in Alpine Vista Subdivision.