The premier race that kicks off the summer running season in Colorado is the BOLDERBoulder, a classic which takes place every year on Memorial Day.

Now that the results are in for this year’s BOLDERBoulder, it’s time to think about other summer races you can do to train for runs on the Fourth of July and beyond.

Check out these tips and race calendars for Colorado summer 5Ks near you. And for runners who are more advanced, this guide goes well beyond 5Ks.

Please note that many of these races have other options, so a half marathon may have 5K and 10K distances as well, and nearly all marathons have half-marathon options. We classified these races based on the most interesting distance for each event. So if you don’t immediately see a 5K option for a race you want to try, look again. There are many additional 5K options tucked inside other races.

5Ks to try running during the summer in Colorado

Fourth of July running races in Colorado

• Greeley Freedom 5K Walk and Run — The 4th of July is one of two holidays that inspire communities to host 5Ks. (Can you name the other one? Stay tuned for the answer.) And this popular race along the Greeley Stampede Independence Day Parade route is finally back after a hiatus of a few years, thanks to run.Windsor. Other fun July 4 5Ks include the Firekracker 5K, the 4th of July Fun Run at Palmer Lake and the Burro Buster 5K in Fairplay, a wild romp at high elevation on asphalt, dirt and hills.
• You don’t have to run just a 5K for the Fourth: Aspen has the Boogie’s Buddy Race that includes a 5-miler; there’s a 10k trail run in Breckenridge and a wild 10K in Ouray and half marathons in Castle Rock and Longmont.

Summer 5Ks that take place before and after July 4

• Colorado Rockies Home Run 5K — This race on June 1 gives you the chance to run a lap around Coors Field in addition to downtown Denver. At least someone will touch home plate this year besides Rockies’ opponents.
• Sierra’s Race — This longtime Loveland race on June 15 honors Sierra Krizman, who died of meningitis at age 20, and raises money for the fight against the disease that killed her.
• The Summer Scamper 5K for All — The Scamper is an all-ability race on June 26 that encourages people to get outside and enjoy nature. The Scamper takes place at Denver’s James A. Bible Park and supports the High Line Canal Conservancy’s work to preserve, protect and enhance the historic 71-mile High Line Canal. The Scamper includes a children’s Ditch Dash along with a 5K and a festival.
• Pirates Run for Booty — Grab a coin at the finish of this July 27 race in Thornton. Some coins are worth prizes. Some are race vouchers — because everyone loves more running as a reward for running — but some are worth cash up to $100.
• The Rocky Mountain 5K — The official 5K of the Rocky Mountain State Games takes place on July 27 in Colorado Springs and includes a downtown summer festival, a free Sasquatch Shuffle for kids and a dog bandana for pooches.
• Dash for Smiles — This Denver race, on July 28, has raised more than $140,000 for local cleft pallet clinics.
• Sunrise Stampede — This Longmont race on Aug. 10 is in its 39th year and supports mental health teacher innovation grants and special education.

  

10Ks — This is a hard distance to find beyond the BOLDERBoulder, but there are several good ones available in Colorado, and most have 5K options.

• Into the Wild running festival — This race on June 8 offers a chance to run through the beautiful plains of Keenesburg and the Wild Animal Sanctuary, where you can see rescued animals such as bears and tigers and a free opportunity to tour the place after the race.
• Father’s Day Classic — If you’re feeling ambitious, there’s a 10-miler, too. This Arvada tradition on June 16 includes a free car show.
• The 80s run — A rare evening race at 5 p.m. and a free concert at 7 p.m. by That 80s Band, which features your favorite hip-hop classics from the 2000s (we’re joking), in addition to a plastic cup, big hair and breakdancing contests and an iron-on T-shirt. It takes place at 5 p.m. on June 22 in Littleton.
• Boulder Sunrise Run — Celebrate the Summer Solstice on June 23 around the Boulder Reservoir.
• The Deja Vu 10K — This Brighton July 13 race offers a funny name (because you just loop the 5K course again) as well as twice the distance for just $10 more, which we think is a pretty good deal.
• The Dynafit 10K at 10,000 feet — if you don’t think a 10K is challenging enough, why not do it in much thinner air? This takes place in Vail on July 20.
• The Human Race and Mountain Avenue Mile — Two iconic Fort Collins races in one weekend on Aug. 9-10. The Mountain Avenue Mile takes place Friday night, and if you think a mile is easy, try running it as hard as many of the competitors. A 10K is the best way to run the Human Race, but it also offers a half marathon and a 5K.

  

Half Marathons

• Slacker Half Marathon — This course is terrific both because it’s gorgeous and it’s a fast downhill just begging you to get a PR. It takes place on June 22 at the base of the Loveland Ski Area into Georgetown.
• All Out Dog Days — A July 13 race to benefit second-chance pooches in Westminster and a chance to see what your dog can do as well as you. The fastest dogs get a prize.
• The Rocky Mountain Half — This race runs near the perimeter of Rocky Mountain National Park in a fun tourist town, Estes Park, on Aug. 3.
• Georgetown to Idaho Springs — The unofficial second half of the Slacker, this Aug. 10 race is also fast and scenic.
• The Labor Day Half Marathon — This Sept. 2 race, in Parker, gives you a chance to run off the backyard grilling treats that are a staple of Labor Day.

  

Trail runs — If you’re a dirt diva, Colorado has as many trail races as anywhere in the country.

• Elk Meadow Trail Race — The Town of Evergreen presents a run on June 22 through the rolling hills of Elk Meadow Open Space Park. This race is one of four the town hosts that are suited well for beginner or intermediate trail runners throughout the summer.
• Sunset Trail Running Festival — Choose between a 28K, a 12K or 5K that start and finish on Main Street in Gold Hill and run on U.S. Forest Service roads on June 23.
• The Barr Lake 30K and 15K — A flat and fast course, especially for a trail race, around a gorgeous state park known for birding in Brighton on July 14.
• Spring Creek Memorial Trail Run — A 9.5-mile race on a primitive trail through Steamboat Springs on July 20 that honors Patty Brenner Hagberg, who was struck and killed by a truck along the lower part of the trail in 1991. This race is part of the Steamboat Springs Trail Running Series.
• Holy COW Trail Stampede — A Westminster race that offers a 10K or 5K on Aug. 10.
• Run the Rockies Trail Race — This 5K, 10K or half marathon race leads runners through the Frisco Peninsula trails with views of Lake Dillion and the Tenmile mountain range on Aug. 10.
• Westminster Trail Race — There are many trail races perfect for beginners, and this Aug. 24 race is a great example, a dirt, non-technical trail around a beautiful lake, with 5K, 10K and half-marathon options.
• Black Squirrel Half Marathon — This difficult race through Lory State Park, on Sept. 7, is part of the fantastic Gnar Runners trail series with many challenging races in Northern Colorado.

  

Marathons — We don’t have many marathons in Colorado during the summer. They tend to take place in the fall, when it’s cooler, unless they are at higher elevations.

• Estes Park Marathon — Billed as one of the most scenic road marathons in the U.S., Forbes Magazine rates it as one of the top seven in the U.S. It takes place on June 16.
• The Leadville Trail Marathon and Heavy Half — This race takes place June 29 in the iconic running town of Leadville and is sold out, but if you’re dying for a chance to run the highest and self-described hardest marathon in the country, you can get on the waiting list.
• Aspen Valley Marathon — See beautiful Aspen from your shoes on July 13.
• Boulder Rez Marathon — If you don’t mind the heat, you can run this scenic, four-lap course around the Boulder Reservoir on Aug. 3.
• The Fall Equinox — Enjoy the wild scenery of the Poudre River all the way down the canyon near Fort Collins on Sept. 22, a perfect chance to PR both because of the downhill course and the cooler September weather.

Ultramarathons — Colorado is packed full of ultramarathons, which is great for when 26.2 miles just isn’t enough to quench your thirst for a solid summer race.

• 12-hour Last Man Standing Event — This race follows the Big’s Backyard Ultra format, which is something kids would dream up, if they were sadists. Competitors run 4.1 miles every hour until they stop or, if you’re hardy, for the entire 12 hours. It takes place June 22 in Windsor.
• Chase the Moon 12-hour endurance run — This one isn’t quite as Game of Thrones as other Colorado ultras, as you’ll get the chance to run all night through foothills on the Highlands Ranch Backcountry trail system on July 19, and you can run as much as you want. There’s also a 50K option. It’s part of the Aravaipa Running series, and you can join up with friends or family if you don’t want to run the entire 12 hours yourself.
• Sheep Mountain Ultras — A 50K, 50-miler or measly half marathon in Fairplay, nearly all of it above 10,000 feet. The Aug. 3 race is part of the challenging but excellent Human Potential running series.
• Leadville 100 — Many of the more famous and difficult ultras in Colorado are also difficult to get into, and this Aug. 17 masterpiece is no exception. But it’s a fun race to watch, if you can control your FOMO, or even help crew or pace a runner.

Triathlons — We know some of you prefer to swim, bike AND run, so here’s some races for you freaks as well. Most offer Olympic and Sprint distances.

• Loveland Lake to Lake — This classic race takes place June 22.
• Boulder Peak — Another classic, this one takes place July 14 around the reservoir in Boulder.
• Steamboat Lake — A chance to race in Steamboat on July 28.
• Harvest Moon — This race offers a half Ironman-distance tri, where you swim 1.2 miles, bike 56 and run a half marathon, in Boulder on Sept. 7. Whew.

  

Obstacle Races — You might as well throw some barbed wire, rope climbing and lots of mud into a race, right? Many of these obstacle races are now defunct, but these two stalwarts remain.

• The Spartan — The OG offers more than a dozen obstacles into a 5K, 10K, 21K or, gulp, 50K (with 60 obstacles) on June 15-16 in Colorado Springs.
• Tough Mudder — A 5K, 15K or eight-hour infinity course on July 20-21 in Fort Carson.

Bonus. What’s the other holiday that inspires 5Ks in Colorado?

For those of you who like to solve riddles, the other holiday that’s popular for 5Ks is an especially good day to get some exercise before you eat a giant meal. It’s Thanksgiving, of course, when you can enjoy a turkey trot before your turkey feast.