Steamboat Springs Cross country skiers at the Steamboat Ski Touring Center will be going underground next winter if only for a few moments at a time.
Steamboat Boulevard is closed at the bridge over Fish Creek until July 26 while crews from Native Excavating install a tunnel under the road. It is being built to accommodate skiers in winter and hikers and cyclists in summer.
The project was a condition of city approval for the latest phase of the Sanctuary luxury home subdivision being developed by Country Club Highlands partnership. The development group is led by Martin Hart, former principal owner of the Steamboat Ski Area.
The 40-foot-long tunnel is part of a larger project that includes a 95-foot-long concrete bridge over Fish Creek and realignment of the trail downstream from the bridge.
Project engineer Bob Furman of Civil Design Consultants said the upstream portion of the trail will also be improved.
Subdivision documents on file with the Routt County Clerk and Recorder show the preconstruction cost estimate for the tunnel and the bridge was $300,000. The developer is footing the entire bill.
The creation of the new phase of the subdivision on the south side of Fish Creek triggered a long contemplated roadway linking north and south Steamboat Boulevard. The developer also paid for the new road.
However, the new road connection interrupted a key cross country ski trail that travels around the back nine of the Sheraton Steamboat Golf course. The interruption created the need for skiers to stop and take off their equipment to cross the road, touring center owner Birgitta Lindgren said.
"The tunnel will eliminate a road crossing and it should be much safer," Lindgren added.
The touring center has lost some terrain because of the development of the subdivision, but the new road crossing had particularly increased the difficulty of hosting cross country ski races.
During summers, the trails will be maintained and managed by the city of Steamboat Springs for walking and bicycling. There is a public easement in the area during the summer. During winters, there is a private easement to protect the integrity of the commercial touring center. In winter, the trail is not public.
City Director of Parks, Open Space and Recreation Chris Wilson called the trail corridor along Fish Creek a significant piece of public access.
"The city has always supported underpasses wherever we can get them in, so we aren't mixing various uses," Wilson said. "This will make a great trail connection through the Sanctuary development. We're very appreciative of Martin Hart working with us to maintain public access in that critical area."
Wilson said Hart also supplied $50,000 to support improvement of Nordic trails at Howelsen Hill to offset some of the lost terrain in the Sanctuary.
Speaking for the developer, local attorney Bob Weiss said Hart has complied with everything the city has asked him to do.
"The trail there is gorgeous and they have finally perfected it," Weiss said. "I've already been riding my bike through there."
The new bridge was built to be able to withstand the weight of the touring center's Bombardier snowcat for grooming purposes. But the tunnel isn't large enough for that equipment.
Furman explained it wasn't possible to build the tunnel large enough for the Bombardier because it could not be dug below the water table of Fish Creek. As it is, an "under drain system" has been built into the ground below the tunnel to ensure groundwater drains away efficiently.
Lindgren is hopeful water seeping into the tunnel will not create icy conditions during the winter.
Furman, who enjoys skiing at the touring center himself, said drainage gutters and a sill were designed at the entrance and sides of the tunnel. However, it wasn't practical to install an interior drainage system in the tunnel.
It will be built of precast concrete and will measure 9 feet high and 12 feet wide. Solid concrete barriers will be installed as railings along the roadway over the tunnel. They are intended to reduce the likelihood that snowplows will plow snow and sanding materials down onto the trails below.
"It's a new experience for all of us," Furman said.
The bridge is extra wide to accommodate the 18-20 feet required by the blade on the front of the Bombardier. It is engineered to hold the weight of 12 to 18 inches of packed snow as well as the weight of the grooming equipment.
It was necessary to build the bridge 95 feet long to span the flood zone of Fish Creek, Furman said. It is high enough to accommodate the passage of kayakers beneath it during high water.