Running Races & Run Clubs in Douglas County
By Connor Tien, DougCo Social · Updated August 2026
Every race worth putting on the calendar — from a Thanksgiving 5K that fills the fairgrounds to a 50K ultra on the Ridgeline trails — plus the free run clubs that meet six days a week across Castle Rock, Parker and Lone Tree.
The Douglas County race calendar
Dates below are the 2026 running of each race. Most are the same weekend every year, so this doubles as next year's planning list.
| Date | Race | Distances |
|---|---|---|
| Sat, Mar 14 | ShamROCK StampedeDouglas County Events Center, Castle Rock | 10K (RRCA Colorado State Championship), 5K, free 1K Kid’s Sham-Scram |
| Sat, May 9 | HRCA Mother’s Day 5KHighlands Ranch | 5K |
| Sat, Jun 13 | Climb4ChangeCastle Rock | 5K, trail, stairs |
| Sat, Jun 20 | Dash Across the DamParker | Father’s Day 5K |
| Sat, Jul 4 | July 4th ROCK-IT RUNDouglas County Events Center, Castle Rock | Half marathon w/ relay (6:30 a.m.), 5K (8 a.m.), free 1K, post-race concert |
| Sat, Jul 4 | HRCA Independence Day 5KHighlands Ranch | 5K |
| Sat, Aug 8 | Reece’s RoundupMiller Park trail system, Castle Rock | 5K trail run, 1-mile walk |
| Sun, Aug 30 | Bluffs 8K Trail RunPrairie Sky Park start, Lone Tree | 8K trail |
| Sat, Sep 26 | HRCA Oktoberfest 5KHighlands Ranch Town Center | 5K |
| Sat, Oct 3 | Castle Rock Trail FestivalMiller Park + Ridgeline Open Space | 50K ultra, half marathon, 10K, 5K, liveBIG Family Adventure Run |
| Thu, Nov 26 | Turkey ROCK TrotDouglas County Events Center, Castle Rock | 5K fun run/walk, free 1K Kid’s Dash |
The ROCK n RUN Series
Three of the county's four biggest races come from one Castle Rock outfit: RUN to Change Lives. All three start at the Douglas County Events Center, 500 Fairgrounds Drive, and all three run as fundraisers. You can register for any one on its own, or take the series — which locks early-bird pricing across all three, adds a VIP fast pass for the food and drink lines, and earns a three-piece magnetic medal that only connects if you finish all three.
- ShamROCK Stampede — Sat, March 14
The St. Paddy's weekend race, in its 8th year, and the one with a real competitive field: the 10K doubles as the RRCA Colorado State Championship. There is also a 5K, a free 1K Kid's Sham-Scram, an indoor health expo and live music on the course. Proceeds go to the It's A Calling Foundation and Live Free Association, which work on PTSD and mental wellness for veterans and first responders. - July 4th ROCK-IT RUN — Sat, July 4
The distance day of the series, in its 6th year. Half marathon (relay option) off at 6:30 a.m., 5K at 8 a.m., free 1K Little Rock-It Run for 8-and-under, then a free post-race concert. There is prize money for the solo half — $300, $200 and $100 for the top three men and women. A virtual option exists if you are out of town. - Turkey ROCK Trot — Thu, Nov 26 (Thanksgiving)
The big one. Now in its 22nd year and billed by organizers as Castle Rock's largest attended running race. 7:30 a.m. start, 5K fun run/walk/stroll, a free 1K Kid's Dash, indoor expo and a DJ at the start line. Proceeds benefit the Help&Hope Center, which serves Douglas and Elbert county residents facing economic crisis or homelessness.
The same group also backs Reece's Roundup (Sat, Aug 8) under its “Powered by RUN to Change Lives” banner, though that one is produced separately. It is a 5K trail run and 1-mile walk on the Miller Park trail system, now in its 21st year, raising money for Reece Rubino — a Castle Rock kid diagnosed with Type 1 Spinal Muscular Atrophy at three months old, whose family has run the event since 2005.
Free run clubs, six days a week
You do not have to wait for a race. Between RNK Running and Walking and the breweries, there is a free group run almost every day of the week. All of these are free and open — show up.
Trails & Ales Run Club
6:00 p.m.105 West Brewing, Castle Rock — The brewery run. A mountain-bike version runs the same time on Wednesdays.
RNK Trail Run
5:30 p.m.Rotating trailhead — see Lost Canyon Ranch — Moves each week — Lost Canyon Ranch, Dawson’s Butte, Memmen Ridge, Hidden Mesa, McMurdo Gulch, Kinney Creek, Castlewood Canyon.
Run Club at Lone Tree Brewing
6:30 p.m.Lone Tree Brewing Company — The north-county option, and the only regular club in Lone Tree.
Chog (Chill Jog)
6:00 p.m.RNK Running and Walking, Castle Rock — Exactly what the name says — the low-pressure one.
Saturday Long Run
7:00 a.m.RNK Running and Walking, Parker — The weekly mileage anchor. Becomes a marathon-training run in the fall.
Lost Runners Run Club
8:00 a.m.Lost Coffee, Castle Rock — Coffee shop start, coffee shop finish.
Club nights occasionally move for weather or holidays. Each week's confirmed runs show up on our events calendar.
Where to run trails
Trail running is what Douglas County actually does best — the Ridgeline system alone carries a 50K. The rotating Monday trail run is the easiest way to learn the network without planning it yourself; it cycles through Lost Canyon Ranch, Dawson's Butte, Memmen Ridge, Hidden Mesa, McMurdo Gulch, Kinney Creek and out to Castlewood Canyon.
- Ridgeline Open Space + Miller Park (Castle Rock): The county's marquee trail network, and the ground the Trail Festival's 50K, half marathon, 10K and 5K all run on.
- Bluffs Regional Park (Lone Tree): Fine crushed gravel with rugged, steep pitches and long Front Range views. Home of the Bluffs 8K.
- Castlewood Canyon State Park: The destination run — canyon rim and creek-bottom trails, about 20 minutes east of Castle Rock. Our full guide →
- Lost Canyon Ranch Open Space (Castle Rock): Quieter and rolling, a regular stop on the Monday club rotation.
Coming up next
Thu, Aug 27
Chog (Chill Jog) with RNK Running
RNK Running and Walking · Free
Sat, Aug 29
Saturday Long Run with RNK Running
RNK Running and Walking · Free
Sun, Aug 30
Bluffs 8K Trail Run at Bluffs Regional Park
Prairie Sky Park · $38.35
Sun, Aug 30
Lost Runners Run Club with RNK Running
Lost Coffee · Free
Mon, Aug 31
RNK Monday Trail Run: Kinney Creek Trail
RNK Running and Walking · Free
Mon, Aug 31
Run Club at Lone Tree Brewing
Lone Tree Brewing Company · Free
Thu, Sep 3
Chog (Chill Jog) with RNK Running
RNK Running and Walking · Free
Sat, Sep 5
Saturday Long Run with RNK Running
RNK Running and Walking · Free
Sun, Sep 6
Lost Runners Run Club with RNK Running
Lost Coffee · Free
Thu, Sep 10
Chog (Chill Jog) with RNK Running
RNK Running and Walking · Free
Sat, Sep 12
RNK Marathon Training Run: 16 Mile & 10 Mile
RNK Running and Walking · Free
Sat, Sep 12
Saturday Long Run with RNK Running
RNK Running and Walking · Free
Frequently asked
What running races happen in Douglas County?
The biggest are the three ROCK n RUN Series races produced by RUN to Change Lives at the Douglas County Events Center in Castle Rock — the ShamROCK Stampede in March, the July 4th ROCK-IT RUN, and the Turkey ROCK Trot on Thanksgiving morning, which organizers call Castle Rock’s largest attended running race. Beyond the series: the Castle Rock Trail Festival at Miller Park in October (50K, half marathon, 10K, 5K and a family run), Reece’s Roundup in August, the Bluffs 8K Trail Run in Lone Tree in August, and HRCA’s 5Ks in Highlands Ranch on Mother’s Day, July 4th and at Oktoberfest.
Is there a free run club in Douglas County?
Yes — six days a week, all free. RNK Running and Walking hosts the most: a Saturday Long Run at 7 a.m., the Lost Runners Run Club at Lost Coffee Sundays at 8 a.m., a Thursday evening Chog (Chill Jog) at 6 p.m., and a Monday trail run at 5:30 p.m. that rotates trailheads. On the brewery side, the Trails & Ales Run Club meets Mondays at 6 p.m. at 105 West Brewing in Castle Rock, and Lone Tree Brewing hosts a Monday run club at 6:30 p.m.
When is the Turkey ROCK Trot?
Thanksgiving morning — Thursday, November 26, 2026, with a 7:30 a.m. start at the Douglas County Events Center, 500 Fairgrounds Drive in Castle Rock. It is the 22nd running. The event is a 5K family fun run/walk/stroll plus a free 1K Kid’s Dash, with an indoor expo. Proceeds benefit the Help&Hope Center, which assists Douglas and Elbert county residents in economic crisis.
Is there a half marathon or ultramarathon in Douglas County?
Two. The July 4th ROCK-IT RUN includes a half marathon with a relay option, starting at 6:30 a.m. at the Douglas County Events Center. The Castle Rock Trail Festival in October is the bigger day for distance runners — a Ridgeline Trail Half Marathon and a Ridgeline 50K ultramarathon on the Miller Park and Ridgeline Open Space trails, alongside a 10K, a 5K and a family obstacle run.
What is the ROCK n RUN Series?
A three-race series from RUN to Change Lives covering the ShamROCK Stampede, the July 4th ROCK-IT RUN and the Turkey ROCK Trot. Registering for the series instead of individual races locks in early-bird pricing on all three, adds a VIP fast pass for food and drink lines, and earns an exclusive three-piece magnetic medal — one segment per race, collected after each one.
Are there trail runs in Douglas County?
Yes, and they are the county’s strength. The Castle Rock Trail Festival runs on the Ridgeline Open Space system, Reece’s Roundup uses the Miller Park trail system, and the Bluffs 8K covers fine crushed gravel with rugged, steep sections around Bluffs Regional Park in Lone Tree. For free weekly trail miles, RNK’s Monday trail run rotates through Lost Canyon Ranch, Dawson’s Butte, Memmen Ridge, Hidden Mesa, McMurdo Gulch and Castlewood Canyon.
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