Event details subject to change. Please confirm all information via event website.
Behind the Rocks Ultra
Behind the Rocks Ultra starts and finishes at the Behind the Rocks Trail, along the border of the Behind the Rocks Wilderness Study Area. Moab's last hidden gem; its tall standing Navajo Sandstone domes and fins can be seen from many places along the course. This course traverses some remote trails, and give you the […]
Polar Plunge 5K
Are you ready for the COOLEST event of the season! Whether you're a daring plunger, a speedy 5K runner/walker, or a thrill-seeker ready to do BOTH, the Polar Plunge & 5K promises non-stop excitement and heart-pumping fun - all while supporting Special Olympics Colorado. Take the plunge into a chilly pool, dash through the 5K, or double […]
City Park Circuit
Denver Athletics brings you the Denver Park Circuit Series- Three races at Denver's iconic city parks with the same format: One Lap As Fast As You Can Go! Spring- The City Park Circuit Summer- The Cheesman Park Circuit Fall- The Wash Park Circuit Become a Denver Athletics Road Racing Member ($100) or Full Member ($175) and get free entry […]
All Hands on Deck Pirates 5K
This fun packed 5k is Presented by Give It Forward. Bring your entire family. It's All about community. Every child deserves a great start to the school year—but not every family can afford the supplies to make that possible. That’s where Give It Forward steps in. Our annual School Supply Drive brings the community together […]
Cryogenic Cannibal Chase
Planning on some degenerate behavior at Frozen Dead Guy Days? Start your morning off right with an 8k ripper around Lake Estes. This race is the morning pre game for FDGD where you'll score a sick beanie and a hearty breakfast bagel from Village Bagels before the festival kicks off.
RMRR Spring Marathon Training Series #1
Platte River Trailhead Park Colorado Blvd and E 88th Ave, Thornton, CO, United StatesThese Marathon training races are geared towards people training for spring marathons. They are supported runs with aid stations and are timed and scored. There are both 10 mile and 20-mile distances for people who are training for either a half marathon or a full marathon. Come and join us for a fun, competitive training […]
Equinox Half Marathon
Both races start & finish at Sparge Brewing in Wellington 3999 GW Bush Unit 101, Wellington, CO 80549
Tortoise & Hare 12K
Cottonwood Glen Park 3074 S Overland Trail, Fort Collins, CO, United StatesThe Tortoise & Hare (T&H) is a low-key “handicap” series of seven races that are run monthly from October to April, typically on the first or second Sunday of the month. Computer-predicted times allow runners of all levels to compete equally. Runners start at staggered intervals with faster runners (Hares) trying to catch slower runners […]
Splash & Dash II
Louisville Recreation and Senior Center 900 Via Appia Way, Louisville, CO, United StatesJoin us for a Kids’ Splash & Dash Series this winter at the Louisville Rec Center! Get ready for a fun, energetic winter racing experience! Each event features an indoor swim in the Louisville Rec Center pool, followed by a run on the outdoor trail. In the case of bad weather, the run will move […]
Cayson Pearson Memorial 5K
This annual fun run/walk (& knockout tournament if you also love basketball) is held each year to honor the memory of Cayson Pearson, award scholarships, raise funds for additional and future scholarships, and raise awareness for mental health & suicide prevention.
PPRR Nielson Challenge
North Monument Valley Park 1794 Culebra Ave., Colorado Springs, CO, United StatesRace Format The first time you run this event, you'll establish a base time for yourself. This base time is used to generate a handicap time. The handicap time is calculated using an algorithm developed by Bob Royse, and it's geared to favor a beginning runner and the slower runners. Click here for an explanation of the […]
Running Up for Air
The Up For Air Series is a collection of endurance events created to support improved air quality, while having fun hiking and running on great trails with good people. Proceeds from Up For Area events are donated to non-profit groups; the event directors receive no payment. Salt Lake City resident Jared Campbell started Running Up […]
Easter Bunny Hop
This family-friendly 5K is designed for runners, walkers, families, and anyone who loves welcoming spring in a fun and festive way. Whether you’re chasing a personal best or strolling the course with friends, the Erie Easter Bunny Hop is the perfect way to get outside and celebrate the season. 🌷 What to Expect: Professionally timed […]
Desert RATS Trail Running Festival
Desert Rats Trail Running Festival by UTMB has four unique distances, three days of racing and indescribable views of the desert. There is something for every runner. Enjoy views of the Colorado River as you race through flowy singletrack, climb up the mesa, and take in the vastness of the desert.
Run the Ranch Trail Runs
For the 5th year running and benefiting the Heart J organization, we are bringing back an amazing and beautiful trail race to Loveland, CO. You will have 6 distances to choose from. Come run on beautiful trails on private land at Sylvan Dale Guest Ranch. The views alone are to die for! There are different […]
NoCo Urban Ultra & Relay
A collaboration event between run.Windsor and Breakaway Athletic Events celebrating the Poudre River Trail. This long-distance race takes you on a sprawling tour of Northern Colorado via the picturesque Poudre River Trail. You'll enjoy scenic views and local amenities through Fort Collins, Timnath, Windsor and Greeley. While ultra distances can be daunting, this race is an ideal option for […]
Mountain Ridge Trail Race
Mountain Ridge takes place near Highlands Ranch primarily on the Douglas County East-West Regional Trail. This gently rolling course will keep the Heart Rate pumping while offering some of the best views in the front range. The Mountain Ridge Trail Race will once again start and finish from Mountain Ridge Middle School, and offer 100% […]
RMRR Spring Marathon Training Series #2
These Marathon training races are geared towards people training for spring marathons. They are supported runs with aid stations and are timed and scored. There are both 10 mile and 20-mile distances for people who are training for either a half marathon or a full marathon. Come and join us for a fun, competitive training […]
Amasa Trail Race
Amasa Trail Race is a 25K, 15K, 10K through one of Moab's most prized trail systems. Run past petroglyphs, the famous whale rock, red rock, canyons, and the Colorado River, as you experience the desert in the spring time.
Run Through the Decades
Step back in time and hit the streets to the soundtrack of three iconic eras at Run Through the Decades—a race that celebrates the unforgettable music of the 60s, 70s, and 80s! Whether you love the soulful rhythms of the 60s, the funky grooves of the 70s, or the neon-charged energy of the 80s, this […]
Dash for Detection 5K
Be part of a movement at Denver's City Park for our 5K event dedicated to raising awareness about oral cancer. Oral cancer can affect any area of the mouth and is influenced by risk factors such as tobacco and heavy alcohol use, as well as HPV infection. Symptoms to watch for include non-healing sores, lumps, […]
Rockin’ on the River 5K
Hudson Gardens and Event Center 6115 S Santa Fe Dr, Littleton, CO, United StatesDust off your well-loved t-shirts and show 'em off at the Rockin' on the River 5K! Pre and post-race music and entertainment for all. Take in the view along the beautiful South Platte River on the Mary Carter Greenway in Littleton.
CMRA Clear Creek 5K
This race will head west from Prospect Park on the Clear Creek trail on the north side of Clear Creek. There will be a turnaround and part way back there is a bridge crossing where runners will run on a dirt path on the south side of the creek. There will be another bridge crossing […]
ASDAsh 5K to Beat Tooth Decay
Join us for the University of Colorado School of Dental Medicine's 6th Annual ASDAsh 5K to Beat Tooth Decay! We are excited to share that our 5K course has been revamped this year to offer a fresh new route through campus. This year, we will be starting and ending at the LIBRARY COMMONS! Additionally, we're […]
Danico Brewing 5K
Danico Brewing Company 18490 East 66th Ave, Denver, CO, United StatesJoin us for the Danico Brewing 5k, and great, local craft beer at Danico in northeast Denver on April 11, 2026 Join us for the Danico Brewing 5k on April 11, 2026, for a 5k fun run event that starts and ends at this awesome taproom in northeast Denver. Run, walk, jog - whatever goes! […]
Denver Distance Classic
Good Boys Running Club, Denver Athletics, New Balance, and Runners Roost are partnering to bring you a distance-based all-comers track meet under the lights of Randy Penn Stadium. The event will feature 5 events from 400-5000 meters as well as a free 4x400 relay with music, an emcee, prizes from New Balance and Runners Roost […]
Spring Fling Prairie Dog Half
Apex Center 13150 W 72nd Ave, Arvada, CO, United StatesWelcome to the SPRING FLING Prairie Dog Half, part of the Prairie Dog Half Race Series. This spring-time event also features 10k & 5k distances!
Elevate Kids 5K/10K
Our mission is to help elevate kids' lives by using unique fundraising efforts to raise awareness for and donate the funds to non-profits that help kids. We do what we do with Elevate Kids because we have a big warm spot in our hearts for Kids Aid. They provide a service to help kids in […]
RMRR City Park 4M
City Park - Denver 2001 Steele St, Denver, CO, United StatesEveryone – slow, fast, or in-between – can win at RMRR Trophy Series races. With our handicap scoring system, we predict YOUR finish time based on recent running results, giving you a great goal to shoot for whatever your speed. Just show up an hour before the start and we’ll get you ready for your race. It’s an […]
Boulder Track Series #1
Niwot High School 8989 Niwot Road, Niwot, CO, United StatesWe are pleased to offer 2 x Spring track meets (4/12 & 5/3), for middle distance and distance runners, that will be conducted similarly to the BMC (British Milers Club) meets. All meets will be held at Niwot High School (8989 Niwot Rd, Niwot, CO 80503). ADDITIONAL NOTES There are NO age restrictions for the […]
Please click here to submit your event for FREE to our online calendar.
We do not allow events without physical locations (IE – virtual runs, runs with locations TBD, etc…).
Please allow 48 hours after submission for an event to appear on the calendar. If you have already listed your event and would like us to update it, please contact us.