There are no urgent road improvement projects that rank above Maroon Creek bridge - that's why county commissioners are willing to allocate up to $900,000 for replacing the aging span.

The Pitkin Board of County Commissioners said it will contribute almost $1 million toward the project at a work session on Tuesday. The money, depending on how much is needed, will come from revenue left over from an expired Pitkin County tax passed by voters 15 years ago.

The 3 percent tax was paid when contractors purchased building materials from outside the county for projects within the county, said Temple Glassier, the county's deputy public works director.

The tax ended after 10 years and was specifically meant for road improvement projects in the county, including Highway 82. Right now, Glassier said, the county has $1.8 million left from the tax collection.

Glassier said public works would not have wanted to give the money to the Colorado Department of Transportation if there were other more pressing projects on the roads in Pitkin County.

The Maroon Creek bridge, which is a converted railroad trestle built in the 1880s, repeatedly receives low safety ratings from state highway engineers. It is a top priority on a list of statewide transportation projects. In November, legislators announced that they had more than $10 million for a replacement project.

Joe Elsen, CDOT program engineer in Glenwood Springs, said the best estimates so far put the project at $11.4 million. So he asked Pitkin County to provide $900,000 to fill the gap. If the project is more than $11.4 million, Elsen said, CDOT will find a way to cover the remaining cost.

"Right now, we're in the process of designing, and it's a very compressed design schedule, taking bids by February 3," he said. "So it's like when you're building a house, and you have an idea what it should cost, but as you flesh it out it comes together at the end. Our best estimate is in the $11.4 million range."

Naomi Havlen's e-mail is nhavlen@aspentimes.com