Best Colorado trail and running races for summer 2021

After months of canceled races and virtual events, runners are eager to return to in-person trail and running races in Colorado.

Race organizers and the American Trail Running Association have worked hard to come up with health guidelines and new rules to ensure that foot races can take place this summer.

Colorado trail and running races are ‘possible’ in 2021. ‘We’re going to figure this out’

Megan Finnesy, the director of the Dirty 30 Trail Race Series — “two great trail races in two beautiful places” — described some of the new challenges she faces as she works to ensure the success of trail and running races in Colorado during the pandemic.

“I’ve been speaking with park managers, who are concerned about the state’s rules on public gatherings. I’m working to show them that trail running is safe.”

Finnesy is looking at every option, including staggering starts and limiting gathering at the start and finish.

Despite the challenges COVID-19 has created, Finnesy is confident racing will return this summer.

“This is possible. We’re going to figure it out,” she said.

Sign up now

As race directors iron out the details of what trail and running races will look like in Colorado this summer, it’s not too early to sign up for a race.

Many Colorado trail and running races still have spots or have yet to open registration. If your New Year’s resolution was to exercise more or lose your “quarantine-15,” signing up for a trail or running race will provide the perfect financial and psychological incentive to help you stick to your goal.

For new runners who discovered the sport during the pandemic, races offer a chance to test your endurance and meet other runners.

“Running tends to attract a lot of independent people, who like to explore or go out alone, but if you’re looking for a big challenge, it’s nice to have the support a race can provide,” Finnesy said.

Runners at Bolder Boulder Running Race
Photo courtesy of Bolder Boulder

Not to mention, races are fun!

Unlike a middle school cross-country meet, no one’s parents are making them run. Racing is like one big party, where everyone’s earning their runner’s high together. Sign up now and give yourself something to look forward to. Remember what that was like?

What trail or running race is right for me?

Choosing the right trail or running race can be a challenge in its own right. Fortunately, Denver and communities along the Front Range and elsewhere in Colorado have a variety of amazing events at nearly every distance.

If it’s your first race, sign up for something shorter, like a 5k. If you’re more serious about training, or have some running experience, it’s not too late to sign up for a longer race, like a half-marathon or a marathon. There are options for both road and trail races. Think about what type of running you prefer and where you’d like to train. If it’s your first race, road racing can be slightly easier with less technical terrain or climbing.

Once you sign up, the next step is to start training. There are a variety of training plans on the internet for both trail and road racing. Choose a plan that works with your schedule, running goals and fitness baseline. Organizers for some runs, like the Dirty Thirty, offer custom training plans specific to their race.

Trail Runner Racing in Colorado
Photo courtesy of Howie Stern, Dirty 30 Race.

Great Colorado running races for summer 2021

Flamingo Day 5k

Where: Sloan’s Lake Park, Denver, CO
When: June 6, 2021
The Lowdown: If you’re new to running, or looking for something shorter, a 5k is a great distance to start with. At three miles, it’s short enough that nearly anyone can complete it, but it also allows enough challenge if you want to go faster. The Flamingo Day 5k takes place at Sloan’s Lake park. Race organizers offer discounts if you register for a “six pack” of 5k Colorado running races throughout the summer. Race proceeds go to a designated charity.

Pro runners at the Bolder Boulder Running Race
Photo courtesy of Bolder Boulder

Bolder Boulder 10k

Where: Boulder, CO
When: Memorial Day Weekend, May 31, 2021
The Lowdown: Since 1979, the Bolder Boulder has grown to become one of the best-known and well-regarded 10k races in the country. In 2019, over 50,000 people registered. The race attracts all types of runners. It offers running, jogging and walking waves, as well as an international pro race, featuring olympic level runners.

Stay tuned for registration date

Runners at Bolder Boulder Running Race
Photo courtesy of Bolder Boulder

Emerald Mountain Epic — Marathon, Half-Marathon, and Bike Race

Where: Steamboat, CO
When: August 7 and 8, 2021
The Lowdown: Formerly known as the Steamboat Stinger, the Emerald Mountain Epic is a weekend full of trail-racing fun. Race offerings include a half-marathon and marathon, as well as a cross-country mountain bike race. All races utilize the pristine single-track trails above Steamboat and offer wonderful views of town. If you’re feeling ambitious, enter both the mountain bike race on Saturday and the marathon on Sunday. Be prepared — trail running is different than road racing. Each race gains several thousand feet of elevation.

Registration opens February 15

If you don’t want to hit the dirt, check out the Steamboat Marathon, on June 6, 2021, which offers similar scenery while running on tarmac.

Runner racing in Steamboat, CO
Photo courtesy of Noah Wetzel, Emerald Mountain Epic

Colfax Marathon

Where: Denver, CO
When: October 16 and 17, 2021
The Lowdown: The Colfax Marathon is one of Colorado’s most popular running races. The long-standing event offers an amazing tour of downtown Denver and the historic Colfax Avenue. Racers start and finish at City Park, alleviating the need to shuttle to your car. The race takes runners just west of Sloan’s Lake, at which point they turn around and loop through downtown, the Central Business District and return to City Park. Since the city of Denver is relatively flat, this can be a good choice for a first marathon. If you’re not set on running a full 26.2 miles, the race also offers a half-marathon, 10-miler, 5k or relay races. Registration opens in March.

Dirty 30 Running Race Start
Photo courtesy of Howie Stern, Dirty 30 Race.

Dirty 30 50k

Where: Golden Gate Canyon State Park
When: June 12, 2021
The Lowdown: If you’re looking to run your first ultra-marathon, the Dirty 30 could be a great choice. By no means is this an easy race. It’s over 31 miles and includes 7,000 feet of climbing at altitude, all on technical single-track trails. If those numbers haven’t scared you away, you might be the perfect candidate. The Dirty 30 helps first-time ultra runners, providing a custom training plan, course-preview days, happy hour sessions featuring running advice and special recognition for first timer ultra-runners.

The race is set for mid-June and will take place in Golden Gate Canyon State Park, just outside of Golden. Registration is still open, but filling up fast.

Runner at Dirty 30 Running Race
Photo courtesy of Howie Stern, Dirty 30 Race.