Paving of the Colorado Department of Transportation’s U.S. Highway 550 realignment project is planned to begin in the spring, after crews wrap up subgrade and excavation work during the winter.

The nearly $100 million realignment is on track to be finished by its scheduled spring 2023 completion date. Crews broke ground on the massive highway project in August 2020.

The project involves building a new 1.1-mile, four-lane section of highway from County Road 220 to the Grandview Interchange, known locally as the Bridge to Nowhere. In addition to realigning the road, the project includes widening a 3.3-mile section of Highway 550 from County Road 220 to County Road 302 to make it four lanes.

“This is probably the biggest project this area will see for quite some time,” said David Valentinelli, project director. “It’s big, and it’s an exciting thing to be part of.”

In summer and fall, construction crews completed two bridges 250 feet and 600 feet in length, and have excavated material and built up highway subgrade for the highway realignment.

A 1,400-foot detour to carry traffic away from crews during construction of new northbound lanes was also completed. A portion of the detour will become part of the southbound alignment when the project is finished.

Crews realigned the Florida Consolidation Irrigation Ditch to pass through the project. The irrigation ditch transports water for local farms and ranches in the area.

“Now that the structures are built, we have access to the cut materials that will facilitate the construction of the alignment,” Valentinelli said.

Construction will continue through the winter months. Most of the work being done will be excavating materials between County Road 220 and the Grandview Interchange. CDOT hopes that over the winter, crews will complete the subgrade so northbound lanes will be ready for paving come spring.

Valentinelli said the project is designed to increase the capacity, efficiency, mobility and safety of the corridor.

“The current Farmington Hill alignment is very steep and windy,” he said. “I think it’s fairly shaded in the winter.”

A CDOT safety assessment of U.S. Highway 550 between mileposts 13 and 16.5, where the project is taking place, reported 98 crashes from 2015 to 2020. CDOT says 53% of those crashes were caused by vehicles colliding with wildlife. Improvements are expected to reduce accidents with wildlife by 80% to 90%, CDOT said.

“We’re improving safety by enhancing wildlife mitigations,” Valentinelli said. “We’re giving the wildlife places to cross through underpasses, and giving the animals jump-outs if they do happen to get caught in the corridor.”

About 19% of vehicle accidents from 2015 to 2020 were rear-end crashes.

Once complete, Valentinelli said drivers who use the interchange will most likely notice the four-lane divided road, the views from the bridge over “Gulch A” and the new wildlife fencing.

When CDOT abandons Farmington Hill, ownership of the property will largely revert to the county. The county plans to remove the asphalt, stabilize the slopes, place topsoil on the old roadbed and reseed the area with native grasses.

Over a five-year study, CDOT determined that about 23,000 drivers a day use U.S. Highway 160 near Farmington Hill, and about 7,200 drivers a day use U.S Highway 550 near the New Mexico border.

The project is primarily being paid for with $54.4 million allocated by the state of Colorado’s Transportation Commission. The remaining funding comes from $29.9 million in CDOT Region 5 Project funding, a federal grant awarded to La Plata County for $12.3 million, $1 million from the Colorado Department of Local Affairs, $500,000 from the Southern Ute Growth Fund, and a combined $500,000 from the city of Durango and La Plata County.

CDOT is working with local tribes to perform an archaeology survey of the areas affected by the project. Archaeologists have uncovered 50,000 artifacts during excavations, including a wide variety of chipped stone tools, whole and fragmentary pottery vessels, grinding implements and ornamental beads and pendants.

Archaeologists also found 10 residential, communal and ceremonial pit-house structures, all dating to sometime between the late 700s to early 800s.

The archaeological survey is an ongoing part of the project. Once complete, the artifacts uncovered will be permanently housed as a collection at the Bureau of Land Management Canyons of the Ancients Visitors Center and Museum in Dolores. An interpretive display focused on the project is planned at the museum in 2023 or 2024.

“As part of the mitigation efforts, we worked with the surrounding tribes, the most involved being the Southern Ute Tribe,” Valentinelli said. “Archaeological efforts have continued to be monitored throughout our excavation activities.”

Valentinelli said a program detailing the archaeological findings will air on Rocky Mountain PBS sometime in the future.

njohnson@durangoherald.com