In June, 1974, Ivan Mullenix, owner of the CHL Spurs, was awarded a "conditional" NHL franchise for the 1976-77 season. With the McNichols Sports Arena already complete by 1975, he looked to enter the NHL a year early, and the league attempted to broker an arrangement whereby Mullenix would acquire the California Golden Seals (then under league ownership) and move them to Denver in lieu of an expansion team. At the same time, the bankrupt Pittsburgh Penguins would be sold to a Seattle group who also held a conditional franchise, which would have been named the Seattle Totems.
The proposed arrangement fell through, and with the continuing franchise difficulties, the NHL called off the 1976-77 expansion. Mullenix accepted an offer from the WHA to join that league for the 1975-76 season. The Spurs were the second WHL refugee to join the WHA, following the Phoenix Roadrunners.
The WHA Spurs claimed most of the players in a dispersal draft from the Chicago Cougars, who had folded in 1975, and some players from the CHL Spurs were also retained.
A Sports Illustrated preview on the upcoming WHA season noted that it was stalwart Gordie Howe's 28th year in major league hockey, and the Spurs' first. The magazine picked the expansion team to finish last in the WHA's Western Division. It also said that unless the Spurs drew well immediately, "Denver's stay in big-league hockey could be exactly 27 years shorter than Gordie Howe's."
The Spurs' first exhibition game, against Howe's Houston Aeros, proved to be a microcosm of their brief stay in the WHA. No beer was available because Mullenix was unable to get a liquor license, there was no flag to face during the national anthem, and the scoreboards didn't work. Only 5,000 fans showed up. The situation didn't get much better during the regular season; they only averaged 3,000 fans in a 16,800-seat arena. The most widely cited reason for the poor attendance was hard feelings over being spurned by the NHL. Denver-area fans had been banking on an NHL team after three years of advertising and did not consider the WHA to be a major league.
The situation wasn't much better on the ice either. Veteran Ralph Backstrom was one of the Spurs' few experienced players, but at 38 his career was in decline. Still, he wound up leading the team with 50 points in 41 games. The rest of the roster was filled with cast-offs and career minor-leaguers, such as Don Borgeson, who had played for the WHL Spurs from 1971–73; he finished second to Backstrom in points scored with 41. They could never find an answer in goal; one of their goalies ran up a staggering 15.00 goals against average (GAA).
The Spurs played their first regular-season game at home against the Indianapolis Racers. Before only 5,000 fans, the Spurs scored the first goal, only to give up seven unanswered goals en route to a 7-1 loss. By December 30, they were in the Western Division cellar with a 13–20–1 mark, despite an overtime win over the Racers that night in Denver. It would turn out to be the last game the Spurs would play in Colorado.
Rumors had abounded even before the Spurs got on the ice that the NHL was planning to move either the Seals or the Kansas City Scouts to Denver. By late December, Mullenix got word that the Scouts were in very serious discussions about moving to Denver for the following season. Knowing he couldn't hope to compete with an NHL team, Mullenix began the process of selling the team to the "Founders Club," a group of businessmen based in Ottawa, on New Year's Eve. He had initially begun negotiations with the Founders Club a month into the season when the first rumors cropped up of a Scouts move to Denver. Soon after Mullenix reopened the Ottawa feelers, the Founders Club insisted that Mullenix move the team to Ottawa immediately. In the middle of a road trip, Mullenix quietly moved the Spurs to Ottawa on January 2, 1976, where they were renamed the Ottawa Civics. The players reportedly only learned of the move to Ottawa when they stood on the ice in Cincinnati (in their Denver colors) and suddenly heard O Canada being played in honor of it being the national anthem of the nation of their new "home city".
Despite playing to sellout crowds at two home games in Ottawa, Mullenix and the Founders Club were unable to reach a deal, and Mullenix was not willing to operate the team in Ottawa. Negotiations for the sale were called off on January 15, however, and the team folded for good two days later. The Spurs/Civics' 41-game existence made them easily the shortest-lived franchise in WHA history, and one of the shortest-lived franchises in North American professional sports history.
The Spurs' abrupt departure turned out to be a prescient move, as the Scouts indeed moved to Denver for the following season, becoming the Colorado Rockies. The Rockies only lasted six seasons, though, before relocating again and becoming the New Jersey Devils. It would not be until the relocation of the Quebec Nordiques (ironically, a former WHA franchise) to Denver as the Colorado Avalanche in 1995 that Denver would enjoy lasting success in major league hockey.
The last active Spurs player in the NHL was Ron Delorme, who retired after the 1984-85 season. As well, Spurs draft pick Mel Bridgman played in the NHL until 1989, but never played in the WHA.