Winter may still have a grip on the forecast, but spring race season is already warming up, and now is the time to start training if you want to hit the start line feeling strong. Whether you’re logging snowy sidewalk miles or spinning indoors dreaming of open roads, the Denver-area race calendar offers plenty of motivation ahead, from approachable 5Ks to bucket-list cycling routes with big views. Here, five spring and early-summer events are worth keeping an eye on: 

• That Dam Run (March 1, Cherry Creek State Park): A spring classic with 5K, 10K and half marathon distances, That Dam Run is perfect for building early season endurance with scenic reservoir views and relatively flat terrain. 
• Boulder Rez Half Marathon (April 11, Boulder): Test your half marathon strength on the Boulder Reservoir course, a popular spring target for locals aiming to PR before summer. 
• Denver Colfax Marathon Weekend (May 16–17, City Park): Colfax Marathon Weekend offers something for every runner: a 5K, 10-miler, half marathon, marathon, as well as relay options. Courses run through City Park, downtown and iconic landmarks including Empower Field and the Denver Zoo. The 5K kickoff is May 16 with the longer distances on May 17.  
• Pikes Peak APEX (June 13–14, Colorado Springs): This two-day off-road cycling event features challenging terrain in beautiful Colorado Springs—a great goal race after spring ride training.  
• Triple Bypass (July 11, Evergreen to Avon): A Colorado cycling legend: 118 miles over three mountain passes. There’s also the 80-mile double option for riders building up endurance. 

Whether you’re chasing a personal record or simply curious about a new distance, getting a head start in winter puts you in prime position for a strong, rewarding spring: one filled with finish-line smiles, scenic routes, and miles you’ll be proud of.