$80 million Clear Creek Canyon project includes 3 miles of trail, 8 bridges and a feat of engineering
Clear Creek Canyon is one of Jefferson County’s most dramatic geological landscapes, featuring towering rock walls and whitewater rapids arrayed along 13 miles of winding two-lane highway leading west from Golden to Clear Creek County.
What it lacks is adequate creek access for visitors to stop and savor its beauty or hike along its banks. The highway, U.S. 6, is off-limits to runners and cyclists because its five dark tunnels are so narrow, and pullouts are scarce — with some posing traffic dangers. Motorists get only occasional glimpses of the soaring canyon walls above because the curving highway commands their full attention.
That’s going to change over the next two years, thanks to an ambitious construction project that will dramatically improve recreational access to the canyon. Jefferson County’s Open Space division is spending $80 million to extend the Clear Creek Canyon trail three miles upstream from its current terminus at Tunnel 1, which is located two miles west of Golden. About 1.25 miles of new trail is slated to open just west of Tunnel 1 next year, with another 1.75 miles to follow in 2026. Eventually the trail will connect with Clear Creek County trails through Idaho Springs and beyond.
If $80 million seems like a lot for three miles of concrete trail, it is. But the complexity of the project, with a narrow creek and highway hemmed in by steep mountainsides, presents major engineering hurdles. In some sections, the trail is being built on elevated concrete viaducts resembling the sweeping roadway decks of Interstate 70 as it runs through Glenwood Canyon.
The project includes seven new bridges over Clear Creek, one new bridge over the highway, a new underpass beneath the highway and two new trailheads with restrooms and parking spaces for 170 cars. A park at one of the trailheads will feature a one-mile loop for hikers and creek access.
“It’s pretty wild,” project manager Scot Grossman said while providing a guided tour of the area in mid-August. “What we’re doing is a generational project.
“This has statewide and national significance,” he continued. “We’re creating safe access to the creek, as well as all the recreational amenities – rock climbing, slack-lining, tubing, rafting, fishing, gold panning. I love the idea of little kids growing up in Golden 15 years from now, they get their little bike posses together on Saturday and ride up the trail to go fishing, climbing, or to ride a lap at Centennial Cone (park) and ride back down.”
“We’re building this for 100 years”
Great Outdoors Colorado — which distributes Colorado Lottery proceeds — provided a $7-million grant for the current construction project. The Denver Regional Council of Governments chipped in another $10.25 million. GOCO previously gave the Clear Creek Canyon trail effort $10.5 million for segments that have already been completed.
But the remainder of the $80 million is coming out of the Jeffco Open Space budget, which is funded by a dedicated 0.5% sales tax that voters approved in 1972. That tax is not subject to the restraints of the TABOR amendment, approved by Colorado voters in 1992, which limits the amount of revenue governments in the state can retain and spend.
“Most of the open space programs around the Front Range have a similar sales tax,” Grossman explained. “Ours predates Tabor by 20 years or so, so there’s no sunset (provision) on it, which is really fortunate for us. Other agencies have a 10- or 15-year sunset, and they have to go back to the voters to re-up their funding.”
CDOT is also working on the project in an effort to create safer motorist access to creek attractions than has been the case in the past. “They’re the other landowner here,” Grossman said. “Their mission is to get people through the canyon safely and efficiently. Our visitors, when they stop, they pull out in every little nook and cranny. Doors open, dogs come out, strollers, bikes. It’s just not a safe environment to recreate in.”
In 1871 a narrow-gauge railway began service in the canyon from Golden to the mining towns of Clear Creek County. The current construction project takes advantage of some of its grades. Prior to the construction of Interstate 70 in the 1960s and ’70s, Clear Creek Canyon was the primary route to the mountains for Denver motorists. .
Now, Jeffco’s Clear Creek Canyon Park is in the process of stretching up the canyon along the creek from Golden to Clear Creek County. The first segment opened in 2021 with the debut of the $19-million Gateway trailhead just west of the intersection of U.S. 6, Colorado 93 and Colorado 58. From there, the existing trail extends 1.75 miles to Tunnel 1.
The Clear Creek Canyon trail will be the middle segment of the greater Peaks to Plains trail, which eventually will extend 65 miles from the foot of Loveland Pass through Georgetown, Idaho Springs and Clear Creek Canyon to the confluence of Clear Creek with the South Platte River in Adams County. It is already complete from the Clear Creek Gateway trailhead to the Platte, near 74th Avenue and York Street, via Golden, Wheat Ridge and Denver.
“We’re building this for 100 years,” Grossman said. “We really want to make sure this is here for three or four generations. That takes time. The geologic, ecologic and hydrologic challenges are immense. We have world-class whitewater here that gets really high in the spring. And, you can see the geologic constraints. We’re in a deep canyon with rock everywhere.”
A floating trail, like a mini-Glenwood Canyon
Construction manager Jeff Hoge, a cyclist, already is looking forward to exchanging his hard hat for a cycling helmet.
“I can’t wait for this,” Hoge said. “I’m a cyclist, I grew up here, and I’ve never been able to ride a bike legally on U.S. 6. That’s exciting. As far as the construction part of it, this is a dream job for a construction manager.”
The three-mile section now being built will climb 300 feet from Tunnel 1 to Huntsman Gulch. All of it will be wheelchair accessible and comply with the Americans with Disabilities Act, which means maximum grades of 5%. The walls of the canyon soar 1,000 feet over the creek, which often is very narrow, which is why construction engineers opted for building a viaduct through those sections. It also has less impact on creekside vegetation, they say.
“This is a heavy civil construction project, but we really pride ourselves on having a really light touch, a really surgical approach, because at the end of the day we are an open-space organization,” Grossman said. “We’re a balance of recreation and conservation.
“That viaduct, I think, perfectly sums up ‘heavy civil’ with a light touch. That is a difficult thing to engineer and build, but the impact on the land is way smaller and lighter than cutting out (a streamside slope) and filling back in,” he added.
To create the viaduct supports, workers drill 30 to 40 feet through surface rock and soil until they reach bedrock. Then they drill another 12 feet into bedrock to anchor concrete columns that will support the deck on which more concrete will be poured for the trail.
“This is our new tool, a ‘floating trail,’ a mini-Glenwood Canyon — same design principles,” Grossman said. “We’re basically building a 10-foot-wide road. It’s like what CDOT is doing on Floyd Hill right now — same concept, just smaller.”
The first new trailhead, about a mile upstream from Tunnel 1, will include a roadside parking lot that can accommodate 40 cars, along with a bridge over Clear Creek to the trail.The second new trailhead, at Huntsman Gulch, will offer a place to park, linger and explore which Grossman calls “a park within a park.” The parking lot will be built to handle 70 cars, and there will be a bridge across the highway to the trail. Another bridge will take visitors over the creek to a secondary trail accessing a shady one-mile hiking loop with a natural surface.
When the Huntsman segment is complete in 2026, it will leave a six-mile gap between Huntsman and a segment of the project upstream that opened in 2017, providing access to Jeffco’s Centennial Cone Park near the Clear Creek County line. Grossman said filling that gap, which would complete Jeffco’s part in the Peaks to Plains trail, could take another seven to 10 years depending on funding.
“This is a really big project,” Grossman said. “There’s a lot of money invested from taxpayers of all kinds — federal, state, local, people who play the lottery.
“I start every presentation I give with how privileged I am to do this, to have the responsibility – which is weighty – to do stuff like this for generations to come,” he added. “I’m just a nameless face three generations from now, but this is a legacy for all of us.”
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