Boulder · United States
Half Marathon races near Boulder
28 races in 2026
next one in 3 days
Race calendar
Upcoming Half Marathon races near Boulder
This week 3
4JUL
Run · road · Half Marathon
July 4th Run 5K/10K/13.1
Centennial · 59 km away
4JUL
Run · road · Half Marathon
July 4th Run DENVER/AURORA
Aurora · 48 km away
8JUL
Run · road · Half Marathon
Sand Creek Half Marathon, 5K & 10K
Denver · 39 km away
JUL 5
11JUL
Run · road · Half Marathon
All-Out Dog Days
Westminster · 22 km away
11JUL
Run · road · Half Marathon
Heatwave Half Marathon - Denver
Littleton · 56 km away
+23 more Half Marathon racesShow fewer ↓
18JUL
Run · road · Half Marathon
Summer Splash Prairie Dog Half, 10k, & 5k
Castle Rock · 74 km away
25JUL
Run · road · Half Marathon
Run for Coffee Lovers DENVER/AURORA
Aurora · 48 km away
31JUL
Run · road · Half Marathon
Rocky Mountain Half & 5K
Estes Park · 42 km away
AUG 11
1AUG
Run · road · Half Marathon
Rocky Mountain Half Marathon & 5K
Estes Park · 42 km away
1AUG
Run · trail · Half Marathon
Winter Park 50K
Winter Park · 44 km away
2AUG
Run · road · Half Marathon
Bound for Boston Marathon & Half Marathon - Denver
Denver · 41 km away
8AUG
Run · road · Half Marathon
All-Out Runapalooza
Arvada · 23 km away
8AUG
Run · road · Half Marathon
Fort Collins Running Summit
Fort Collins · 66 km away
15AUG
Run · road · Half Marathon
Bagel Run 5K/10K/13.1 DENVER/AURORA August
Centennial · 59 km away
15AUG
Run · road · Half Marathon
Boulder Rez Marathon
Boulder
15AUG
Run · trail · Half Marathon
Westminster Trail Races
Westminster · 21 km away
16AUG
Run · road · Half Marathon
Erie Half & 5k
Erie · 20 km away
22AUG
Run · road · Half Marathon
Byers Peak Stampede Half Marathon & 5K Run
Fraser · 47 km away
23AUG
Run · road · Half Marathon
Pioneer Prairie Dog Half, 10k & 5k
Westminster · 22 km away
SEP 9
5SEP
Run · road · Half Marathon
Golden Harvest Half Marathon & 5k/10k - Denver
Denver · 39 km away
7SEP
Run · road · Half Marathon
Labor Day Half Marathon
Parker · 71 km away
12SEP
Run · road · Half Marathon
Run for Mental Health 5K/10K/13.1
Centennial · 59 km away
12SEP
Run · trail · Half Marathon
Snow Mountain Ranch
Granby · 56 km away
12SEP
Run · trail · Half Marathon
Black Squirrel Half Marathon
Bellvue · 69 km away
13SEP
Run · road · Half Marathon
NUN RUN
Centennial · 53 km away
20SEP
Run · road · Half Marathon
Fall Equinox
Fort Collins · 65 km away
26SEP
Run · road · Half Marathon
Oktoberfest Run 5K/10K/13.1 DENVER/AURORA
Centennial · 59 km away
27SEP
Run · road · Half Marathon
Running for Children's Rights to Both Parents - 9 of 50 Half Marathons in 50 States - Colorado
Boulder · 2 km away
Boulder · 80 km
28 races mapped
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Recurring Half Marathon races near Boulder
Races that repeat — weekly, monthly or yearly
Spooky Sprint - Denver
The Spooky Sprint - Denver is a Halloween-themed road race held annually at Chatfield State Park in Littleton, southwest of Denver. As part of the Bodies Race Series, it offers a family-friendly setup with options for a 5K, 10K, half marathon, or an untimed 1 Mile. Younger children have their own untimed dash. The in-person races feature chip timing with live results and awards, and a virtual option allows participants to run independently while still receiving event merchandise.
The race course is a road race within Chatfield State Park, with distances from a 1-mile family option to a half marathon. The expected attendance is in the hundreds, suggesting a focus on local runners, families, first-time racers, and those seeking Halloween-themed fun, rather than a large-scale urban event. Registration includes a custom bib, a designer shirt, and a finisher medal, along with complimentary participant photos and post-race treats. Children aged 10 and under can participate in the dash for free without merchandise. The 5K and 10K events provide reduced pricing for participants aged 12 and under.
Spooky Sprint Denver 5k/10k & Half Marathon
Castle Rock Trail Festival / liveBIG Run
Philip S. Miller Park and the Ridgeline Open Space in Castle Rock serve as the setting for this trail festival, challenging runners on Castle Rock's extensive ridgeline trail system. This event is an athletic gathering, combining serious trail pursuits with a strong community and family spirit.
Runners will navigate the varied terrain of the ridgeline trail system, experiencing the natural contours of Philip S. Miller Park and Ridgeline Open Space. Beyond the main races, the liveBIG Family Adventure Run offers a dedicated family obstacle course for children ages 5 to 12, ensuring an engaging experience for younger participants and an inclusive atmosphere.
The Long View Marathon
The Long View Marathon runs point to point between Fort Collins and Loveland in northern Colorado. The full marathon begins at Edora Park and concludes at Fairgrounds Park. The same finish area hosts the half marathon, which starts at Fossil Creek Park, and a 5K centered on Fairgrounds Park. The races occur in October, with staggered morning starts for the marathon, half marathon, and 5K.
The route incorporates sections of the Long View and Front Range bike paths, meaning the longer races utilize a paved-path corridor instead of a closed downtown loop. Packet pickup is available at Altitude Running in Fort Collins prior to race day and at each race’s start area on race morning, subject to a strict cutoff. Marathon and half-marathon prizes feature custom works by local artist Amy Hayman, gift cards to local businesses, overall awards, and age-group prizes; the 5K offers overall and masters awards.
Westy Half & 5k
The Westy Half & 5k is a fall running event in Westminster, Colorado, located at 10600 Westminster Boulevard. It features two distances: a half marathon for those seeking a longer morning run, and a 5k for participants preferring a shorter race.
The event is part of the Hometown Race Series, which organizes half marathons and 5k races in communities outside the primary Denver and Boulder metro regions. A notable aspect is the 5k medal policy: all 5k finishers receive a medal, a practice that remains infrequent for this race distance.
Halloween Trick or Trot Run 5K/10K/13.1 DENVER/AURORA
Turkey Trails- Denver
Turkey Trails Denver is an annual Thanksgiving-themed running event in Denver offering a half marathon, 10K, 5K, 1 mile, and a Kid’s Dash. It accommodates various participants: adults can select a longer timed race, families can opt for a shorter distance, and children 10 and under have their own untimed dash.
The half marathon, 10K, and 5K are chip-timed with live results. The 1 mile and Kid’s Dash are untimed. Registrations include a custom bib, designer shirt, and medal. The Kid’s Dash includes a youth-sized shirt and medal. Children can also run the dash for free without swag. The 5K and 10K have youth pricing for ages 12 and under. The finish area provides free photos and treats. A virtual option allows participation remotely while still receiving event gear.
Marathon At The MAC
Marathon At The MAC is a self-paced indoor marathon on the MAC walking track. Participants complete 26.2 miles on their own schedule by walking, jogging, or running a total of 208 laps.
After each walk or run, participants report their lap count to the MAC front counter staff, so the marathon can be built up over multiple visits. Runners and walkers scan in with a MAC Walking Track Pass when they arrive, participants under 18 need an adult with them, and everyone who finishes the full distance receives a T-shirt.
Louisville Trail Race
The Louisville Trail Race offers half marathon, 10K, and 5K distances on dirt trails near Louisville Community Park in Louisville, Colorado. It provides a Front Range trail running experience, allowing both experienced and newer trail runners to select a course suited to their abilities.
The routes are predominantly flat and dirt, utilizing an out-and-back structure on trails surrounding the park. A challenging hill near the finish offers views of the Flatirons and Front Range mountains. This event, now in its second decade, maintains a family-friendly atmosphere with post-race activities encouraging participants to bring guests.
TURKEY TREK (13.1, 10k, 5k & 2k)
The Turkey Trek is a Thanksgiving race series held at Long Lake Regional Park in Arvada, offering four distances: a 13.1-mile Half Turkey, the 10k Turkey Trek, the 5k Turkey Trot, and the un-timed 2k Turkey Toddle. The 5k begins at 8:30 AM MST, with the half marathon starting at 8:40, the 10k at 9:00, and the 2k at 9:10. This staggered start accommodates runners and walkers of various abilities throughout the morning.
The course ascends to a summit at the 3-mile point, featuring the Egg Nog Chug Challenge where participants can drink 5 ounces of eggnog for a chance to win a new pair of shoes. Following the exposed upper section, the path crosses a ridge for a mile before descending the mesa's east side. The route then transitions to a flatter straightaway with hay bales for the Hay Bale Hop Challenge. This clockwise loop returns to the park, and approximately one kilometer from the finish line, racers encounter the Fill Your Pie Hole Challenge, involving pumpkin pie before the final push. Half marathon finishers are awarded a mug.
Run Denver 'Mile High City' 5K/10K/13.1
Run Denver 'Mile High City' 5K/10K/13.1 is a local Denver running event offering 5K, 10K, and half marathon distances, taking place in late November. It functions more like a supported group run than a large race: each wave is limited to approximately 15 to 20 participants, both runners and walkers are accepted, and timing chips are not used.
The atmosphere is intentionally relaxed. Bibs are distributed on race day, participant gifts are mailed out, and organizers can record times by bib number upon request. Waves begin in the morning and are filled sequentially, with a waitlist or virtual run offered once capacity is reached. Participants receive a shirt, medal, and entry into a virtual runner community; the virtual option also includes text-based coaching support prior to the run.
Thanksgiving Gobble Trot Run 5K/10K/13.1 DENVER/AURORA
The Thanksgiving Gobble Trot Run 5K/10K/13.1 is a Denver/Aurora holiday race series offering 5K, 10K, and half marathon distances. Organized by The Best Races, it centers on a Thanksgiving morning running tradition: participants can race, jog, or walk before the day shifts to stuffing and turkey.
The event welcomes families, friends, and local runners, not exclusively competitive athletes. The core idea is to enjoy the outdoors with others, complete a manageable distance, and burn calories before the Thanksgiving meal.
Looking for something else near Boulder?
Other races in the next 90 days
JUL 139 km away
cycling
Denver Rotary Club Cycling to Serve 2026
JUL 861 km away
cycling
HRCA Rocky Gulch Circuit
JUL 1867 km away
cycling
FoCo Fondo p/b Fat Tire
JUL 1870 km away
triathlon
Parker Parks and Recreation Kids' TRY-athlon
JUL 1945 km away
cycling
Winter Park Classics – Race Rendezvous
JUL 2537 km away
cycling
Blue Sky Hill Climb
JUL 2540 km away
cycling
2026 Colorado Park 2 Park Challenge
JUL 2961 km away
cycling
HRCA Badlands Circuit
About Half Marathon races in Boulder
Boulder Base Miles
Boulder hosts 46 Half Marathon races in 2026 within 80 km of the city centre — upcoming dates, recurring series, and other races nearby, all in one place.
Boulder gives runners more than 150 miles of trails, so locals rarely run the same week twice. Mesa Trail rolls from Chautauqua Park with Flatirons views, and the full out-and-back runs half-marathon distance with over 2,000 feet of vert. Mt. Sanitas climbs 1,300 feet in under a mile and a half, so the fitness has nowhere to hide. South Boulder Creek Trail and Bobolink Trail suit chill Z2 days. Boulder Track Club, Elevate Run Club, Fleet Feet Boulder, Avanti Run Club, and RISE Running keep the group calendar busy. Bolder BOULDER 10K, the 2026 Dash & Dine 5k Run Series, and Boulder Marathon give the city its anchor races.
Boulder riders get road, gravel, singletrack, and base miles right out the door. Boulder Cycling Club runs Tuesday Night Rides from Twisted Pine Brewery at 5:30 PM and Thursday Night Rides from Upslope Brewery at 5:30 PM. The long version is 2 km with 500 m of elevation. The short version is 7 km with 275 m. The climb is 5 km with 3,112 m of gain. Wednesday Morning Velo and Valmont Short Track Series keep the race legs sharp.
June through September is the cleanest block for longer runs, steady rides, and cool summer nights. Elevate Run Club has long runs every Saturday at 7 am in the summer months, and locals stack Z2, intervals, and trail days before the afternoon heat matters. Boulder Cycling Club weekly rides resume in March, so road and gravel season ramps before summer really lands. Winter stays pretty damn mild when you put it in perspective. Bike paths are regularly plowed clear, and people ride all winter on fat tire bikes with snow tires. Shady areas hold snow after sunny days, so locals watch the ice and keep moving.