As spring slowly grabs hold of Utah's landscape, a different kind of endurance athlete is taking over. Mountain bikers and trail runners are back in the foothills exploring the Bonneville Shoreline Trail or other popular lines in the dirt.

For many of those, the goal is to train for some of the myriad races and events taking places in this pretty, great state.

Southern Utah will be home to many of the bigger events, and it's possible that no off-road race will be bigger than the American Mountain Classic at Brian Head this August. Featuring four stages, 170 miles and more than 14,000 feet of vertical climbing, the first significant mountain bike stage race in the country will have a prize purse of more than $20,000 and attract racers from around the globe.

The race (americanmountainclassic.com) comes with a steep entry fee of $400 but has classifications for just about everyone and also includes options for two-person teams. Action will begin on Aug. 24 with a 6-mile prologue to determine starting order for the next day's mammoth 55-mile race along the Virgin River Rim Trail.

Stage 2 will test athletes to the core with a climb to more than 11,000 feet on Brian Head before descending back to the resort.

If all that mountain biking sounds too daunting, there is plenty of time left to train and several opportunities to have seasoned cyclists help you. One of the best off-road training camps happens in mid-April in Moab.

Colorado-based JDS Sportcoaching will conduct a five-day camp with numerous rides, coaching sessions and expert advice on everything from handling switchbacks to dealing with 6-foot drops. The camps, which run April 11-15, have options for beginners and experienced mountain bikers. Visit jdssportcoaching.com for more info.

Bicycles, of course, are just one way to show off your fitness and endurance. For many, the only method of transportation needed is a rugged pair of trail shoes.

This Saturday on Antelope Island, the annual Buffalo Run will take Utah's fittest runners along the trails for races ranging from 25K to 50 miles.

More than 250 entrants have registered for the race, which starts bright and early at 6 a.m. for the 50-milers, while others start a little later. Registration is closed, but visit buffalorun.org for information on the race.