When the Lycra-clad riders competing in the USA Pro Cycling Challenge roll into Boulder on Saturday and make a sharp turn up Boulder Canyon, they'll begin following in the wheel tracks of riders who, more than 35 years ago, helped birth professional bike racing in America.

Just like Saturday's route, the Red Zinger Bicycle Classic, which launched in Boulder in 1975, sent riders up Boulder Canyon, north on the Peak to Peak Highway and back downhill into Lyons before returning to Boulder.

The Red Zinger -- started by Celestial Seasonings founder Mo Siegel, who named the race after one of his popular herbal teas -- ran for five years, expanding in scope and prestige each summer, before transforming into the Coors Classic in 1980.

This month, the Boulder Public Library is displaying an exhibit on the Red Zinger, with old photos, newspaper clippings and race brochures, on the bridge over Boulder Creek in the main library branch.

"This is really a Boulder story -- that's one of the things that really turned me on about it," said Douglas Lee, a professional writer who put together the display in collaboration with the Carnegie Branch Library for Local History.

From the beginning, the Red Zinger drew the country's best cyclists, and each year, the race amplified -- swelling in attendance and in geography. The first year, the race included the mountain race, a time trial and a criterium around North Boulder Park. In future years, it added stages across the state, including in Steamboat Springs, Aspen, Vail and Estes Park. By its third year, the Zinger was the only officially sanctioned international bike race in the United States, and it drew teams from across the world. Some called it America's answer to the Tour de France.

"I really think the Zinger was the spark plug for establishing bicycle racing as a popular sport with the American public," Lee said.

After running the race out of the front office of Celestial Seasonings for five summers, Siegel sold the race for $1 to Michael Aisner, who already had helped organize the event for a couple of years, in 1980. Coors became the race's primary sponsor. The Coors Classic continued on in a similar vein to the Zinger through 1988.

Now, the Pro Cycling Challenge has revived Colorado's standing in the international bike racing scene -- and Siegel couldn't be more psyched about it.

"I love it. I love the Pro Cycling Challenge. I ride a bike all the time," Siegel said. "I'm just thrilled about it, and I think they're doing a good job. I'm so glad that we're closing on Flagstaff for the Boulder leg."

And while several stages of the Pro Cycling Challenge resemble the stages from the old Zinger, Siegel said the spirit now is a little different than it was then.

"The Red Zinger was this passion that I had about, 'Get out and cycle and eat health food and drink great tea and be healthy.' I've been kind of a health nut forever," Siegel said. "It was a lifestyle thing as well as a sporting event."

The Pro Cycling Challenge, on the other hand, is primarily a sporting event. But the lifestyle drive of the Red Zinger still lingers, at least in Boulder, where the number of cyclists has exploded since the 1970s.

"When we first started with the Zinger, there were bike riders around, but not very many," Siegel said. "We just have a great lifestyle here, and I think that the bike race back then was a part of that."

Barry Siff, co-chairman of the committee that organized to bring the Pro Cycling Challenge to Boulder this year, said the legacy of the Zinger was on his mind when he fought to get a Boulder stage.

"I have an eight-hour DVD set of all the video that was ever done for the Red Zinger and the Coors Classic," Siff said. "The race at North Boulder Park -- it was insane. Tens of thousands of people were at North Boulder Park. ...

"It was amazing. Boulder, really, was where it's at. To have the Pro Cycling Challenge come to Colorado and not be in Boulder -- in my mind -- would border on outrageous."