The Mountain West Conference's Rams (7-6) also played in the 2008 New Mexico Bowl, which was the team's last trip to the postseason. The Rams defeated Fresno State 40-35.
"This is an exciting day not only for our team and our program, but for fans of Colorado State who have waited five years for the chance to go back to a bowl game," Colorado State coach Jim McElwain said. "I'm especially happy for our seniors, who have really stuck together and made a commitment to each other that they will get to finish their career experiencing a bowl game for the first time."
The Cougars (6-6) are playing in a bowl for the first time since 2003. Washington State finished the regular season with a 27-17 loss to rival Washington in the Apple Cup, but the team doubled its total wins from the year before showing steady progress under second-year coach Mike Leach.
While the Cougars were bowl eligible, it did not mean they were guaranteed a postseason berth. Nine teams from the Pac-12 were eligible with just seven conference Bowl spots.
"There was never any doubt in my mind that we were going to a bowl game," Leach said Sunday night.
Colorado State is 5-7 in the program's 12 bowl appearances, including a run of nine postseason berths during coach Sonny Lubick's tenure from 1993-2007.
McElwain said the team will practice in Fort Collins before departing for Albuquerque on Dec. 18. He announced the bowl invitation after practice.
"We were excited, everyone started cheering. It was just a good moment for the team and the whole program," senior linebacker Shaquil Barrett said. "We had a team meeting after a walk-through practice and Coach announced that we were going to the New Mexico Bowl and everyone started cheering. It was just a relief to finally find out that our hard work has paid off."
Leach said it was unclear when the Cougars would depart.
It will be the first meeting between the two teams.
Washington State athletic director Bill Moos said Sunday that 2,500 fans reserved tickets to the game regardless of where the Cougars were headed.
Moos also said that perhaps "some" of the fans who were on the "No Bowl Tickets" list may get the opportunity to purchase tickets. Moos, who answers all the mail he gets from fans, started the list after he received some particularly offensive notes following Leach's first season with the team, when the Cougars went 3-9.