CEDAR FALLS - Traces of spring and winter clashed with each other at the entrance to Ullrich Park.

Chilly 19-degree winds bristled through thin trees and newly sprouted seedlings. Runners dressed in knit caps, shorts and tights hopped up and down.

Hardly anyone complained as they prepared for CV Adventure's first 5K adventure run. The trail wound up, down and around the hilly terrain of the park. Saturday's run was designed to give the 45 runners a variety of obstacles not normally seen in an average road race, said Jeff Slade, events coordinator for CV Adventure, an outdoors sports promotion group.

"Everything's pretty much frozen right now so watch the downhills, the railroad ties and everything like that," Slade said.

And then the pack disappeared up a narrow trail into the woods. Just under 18 and a half minutes later, the first runner - Jeff Gall of Cedar Falls - crossed the finish line.

CV Adventures organized the race as a way to showcase some of the off-road trails around the Cedar Valley. Volunteers spent parts of the last three weeks prepping the trail for Saturday's race. Six other events are planned for the future.

Slade said planners were trying to make the course as difficult as possible. The trails create a number of challenges for the runners, but it doesn't necessarily add time. A person can expect about 40 seconds added to each mile, he said.

"The short twists and turns, ups and downs are really what make this course difficult," Slade said.

Jeremy Bidwell, of Clarksville, said he'd never ran an off-road race like this before, but found many similarities to his other passion, mountain bike racing. The course had similar track layouts and obstacles, like crossing a half-frozen creek. One non-factor for him was the bitter cold.

"It has to be below freezing before your lungs really feel like they're freezing," Bidwell said.

Charlie Donohue, a Waterloo firefighter, entered the race after hearing about it from a fellow firefighter. He said one of his biggest challenges was finding a rhythm while trying to navigate the hills.

"Your breathing's constantly being disrupted," he said.

The key there is taking advantage of the downhill and flat sections and good recovery, Donohue said.

Besides an overall winner, there were awards for second and third place finishes and a best men's and women's finisher. The group also held a smaller kids race just prior to the adult run.

CV Adventure's next event will be a duathalon - a bicycle and running race - March 20th at Camp Ingawanis in Waverly. For more information go to www.cvadventure.com.

Contact Josh Nelson at (319) 291-1565 or josh.nelson@wcfcourier.com.