Cortez Republican Scott Tipton will keep his seat in Congress after fending off a challenge from his fellow Fort Lewis College graduate, Pueblo Democrat Sal Pace.
At 9:30 p.m., Tipton had 105,000 votes to Paces 76,000, and The Associated Press projected Tipton as the winner.
Unaffiliated candidate Tisha Casida and Libertarian Gregory Gilman together were pulling less than 5 percent of the vote.
Pace spent the day campaigning in his hometown, Pueblo, with Secretary of the Interior Ken Salazar.
But he was beating Tipton by less than 7,000 votes in Pueblo County, while Tipton had staked out a large lead in Mesa County, the districts Republican bastion.
In my second term I remain committed to working across the aisle towards common sense solutions to the problems facing the 3rd Congressional District. We must jumpstart this economy and get Coloradans back to work, Tipton said in a news release.
Pace once portrayed himself as a scrappy fighter to fellow Democrats in the state Legislature, where he served one year as House minority leader. But in his campaign against Tipton, he cast himself as a bipartisan statesman who could speak for all the people disgusted with Congress.
It was Tipton who came out swinging.
All four of his television ads were negative hits on Pace, and none of them mentioned that Tipton was currently serving in Congress.
The Republican tried to tie Pace to President Barack Obamas health care overhaul, and he hit Pace for votes in the Legislature to suspend several business tax breaks.
In their four head-to-head debates, Tipton stressed his record of passing several bills through the Republican-controlled House, all of which had at least a few Democratic votes.
Casida appealed mostly to disaffected Republicans who supported Ron Paul in the presidential race. She was invited to two of the four head-to-head debates during the campaign, where she pushed for a radically smaller federal government and an end to the Federal Reserve.
Tiptons defeat of Democratic Rep. John Salazar in 2010 opened the door for Pace, a former Salazar staffer.
The Western Slope race initially was considered the closest in the state, but it faded to the background as the national parties focused their attention and money on two races in the Denver suburbs.
But Tipton got major help from a $1.6 million ad campaign by Americans for Tax Reform. The group nearly matched the entire $1.8 million that Pace had raised for his campaign by the beginning of October.
Tipton raised more than $2.2 million on his own.
Pace got $423,000 from the Democrats House campaign group and $280,000 from the Service Employees International union, but it wasnt enough to bridge the gap with Tipton.