Castlewood Canyon State Park
By Connor Tien, DougCo Social · Updated August 2026
A hidden canyon on Cherry Creek just outside Franktown — miles of easy-to-moderate trails, the ruins of a dam that broke and flooded Denver back in 1933, and some of the best low-key fall color on the Front Range. Here's the guide: the trails, the dam story, and when to go.
Castlewood Canyon at a glance
| Trails | ~0.5 to 4 miles, all connectable |
| Best loop | Inner Canyon + Lake Gulch + Rimrock (~4.5-mile lollipop) |
| Don't miss | The 1890 Castlewood Dam ruins + the little waterfall |
| Fee | Colorado State Parks pass or $10 daily vehicle fee |
| Dogs | Welcome on leash |
| Entrances | Main (east) off Hwy 83; west off Hwy 86 |
| Where | Franktown, ~5 miles south on Hwy 83 (Douglas County) |
I've hiked it — dropping down into the canyon along the creek and climbing back out past the old dam is the loop to do. It packs a canyon, a creek, rock formations, and real history into a couple of easy hours close to home.
The trails
Castlewood packs a lot into a small footprint. The trails range from about half a mile to four miles and connect, so you can go as short or as long as you want:
- The full loop (~4.5 miles): Inner Canyon + Lake Gulch + Rimrock. Drop into the canyon along Cherry Creek, pass the dam ruins, and climb back out along the rim with big views the whole way. The park's best hike.
- Canyon View Nature Trail (~0.4 mile): Paved and accessible, right by the east visitor center — the easy option with kids or strollers.
- Lake Gulch Trail (~0.9 mile): A short, gentle drop toward the creek with overlooks.
- Creek Bottom & Falls: Follow the creek to the park's little waterfall — a good turnaround.
- Climbing: The canyon's rhyolite walls are a longtime local rock-climbing spot; you'll see climbers off the Climbers trail.
The Castlewood Dam ruins
The thing that makes Castlewood Castlewood is the dam. Local farmers had it built across Cherry Creek in 1890 for irrigation — you can still find the original cornerstone that reads “Castlewood Dam, Erected A.D. 1890.” It never had a great reputation, and on August 3, 1933, it finally let go, sending a wall of water reported around 15 feet high down Cherry Creek and all the way into downtown Denver.
Today the stone ruins still stand in the canyon, right along the trail — big sections of the old dam wall and arch you can walk up to. It's a genuinely striking piece of Colorado history, and the reason a canyon hike here feels like more than just a walk.
Castlewood in the fall
Come October, Castlewood turns into one of the best low-key foliage spots close to home — no mountain drive required. The cottonwoods along Cherry Creek turn deep gold, and the scrub oak on the canyon walls shifts to red and burnt orange against the rock. Plan for roughly late September into mid-October, and the light down in the canyon in the morning is the move.
More color nearby? See our fall colors in Douglas County guide and the Devil's Head aspen hike.
Know before you go
- Two entrances: The main (east) entrance is off Highway 83, about 5 miles south of Franktown, and has the visitor center. The west entrance is off Castlewood Canyon Road from Highway 86.
- Fee: Colorado State Parks pass or $10 daily vehicle fee at the station.
- Go early on weekends: It's a popular spot and lots fill up, especially in fall.
- Bring: Water, layers, and sturdy shoes for the canyon-floor sections. Leash the dog.
- Good for kids: Short easy trails plus the paved Canyon View trail make it an easy half-day.
Frequently Asked Questions
What are the best trails at Castlewood Canyon?+
The classic is combining the Inner Canyon, Lake Gulch, and Rimrock trails into a roughly 4.5-mile lollipop loop that drops down into the canyon along Cherry Creek, passes the old dam ruins, and climbs back out along the rim. For something shorter and easier, the paved Canyon View Nature Trail (about 0.4 mile) and the Lake Gulch Trail (about 0.9 mile) are both great. Trails range from about half a mile to four miles and connect, so you can build the day you want.
What happened to the Castlewood Dam?+
Local farmers had the Castlewood Dam built across Cherry Creek in 1890 for irrigation. On August 3, 1933, the dam failed and sent a wall of water — reported around 15 feet high — down Cherry Creek and into downtown Denver. The stone ruins of the dam and the original 1890 cornerstone are still there today, right along the canyon trails, and they're one of the coolest things to see in the park.
Is there an entrance fee at Castlewood Canyon?+
Yes — it's a Colorado state park, so you need a Colorado State Parks pass or you pay a $10 daily vehicle fee at the entrance. There are two entrances: the main (east) entrance off Highway 83, about five miles south of Franktown, and a west entrance off Castlewood Canyon Road from Highway 86.
When do the fall colors peak at Castlewood Canyon?+
Castlewood is one of the best low-key foliage spots on the Front Range. The cottonwoods lining Cherry Creek turn deep gold and the scrub oak on the canyon walls shifts to red and burnt orange — plan for roughly late September into mid-October, and check a live foliage map to time a specific weekend.
Is Castlewood Canyon good with kids and dogs?+
Yes to both. Leashed dogs are welcome, and the mix of short, easy trails — including the paved, accessible Canyon View Nature Trail near the visitor center — plus the dam ruins and the little waterfall make it a great half-day with kids.
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