Rocky Mountain Arsenal National Wildlife Refuge works well as a short outing from a Denver base: choose one easy walk, then add the Wildlife Drive if time and conditions allow. Allow about two hours on-site for a relaxed first visit, rather than building the day around a guaranteed bison sighting. The refuge is free to visit, with an 11-mile auto route and 20 miles of hiking trails. (U.S. Fish & Wildlife Service)

Entrance, cost and hours

For the main entrance and Visitor Center, navigate to 6550 Gateway Road, Commerce City, CO 80022. From I-70, the official directions use Quebec Street, then Prairie Parkway east and Gateway Road north into the refuge. Keep your existing Denver accommodation for this outing; there is no need to change bases just to visit. (Address; directions)

As checked in October 2026:

  • Admission: Free; no America the Beautiful pass is needed.
  • Refuge roads and trails: Sunrise to sunset in fall, winter and spring; sunrise to 8 p.m. from May 1 through August 1.
  • Visitor Center: Wednesday–Sunday, 9 a.m.–4 p.m.; closed on federal holidays. Its Monday–Tuesday closure does not normally close the outdoor refuge. (Official visitor information)

The entire refuge closes on Thanksgiving, Christmas and New Year’s Day. On Christmas Eve and New Year’s Eve, last entry is 11:30 a.m. and closing is 12:30 p.m. Check current alerts before leaving: sections can close at short notice for weather, wildlife needs or projects. (Rules and closures)

Choose one walk, then add the drive

Shortest option: Lake Mary

For a modest walking commitment, choose the 0.6-mile Lake Mary Loop, with a boardwalk and piers overlooking the water. Park at the Lake Mary Learning Center or the small lot at the base of the lake. This is a useful choice when someone wants a walk but not a longer prairie route.

If you prefer to start at the Visitor Center, take the 1-mile Discovery Trail from its back patio. It passes the black-footed ferret exhibit and connects with Lake Mary for those who want to extend the walk. Do not approach the bison fence along Discovery Trail.

Longer option: Lake Ladora

Choose the 1.8-mile Lake Ladora Loop instead of stacking several short walks. It follows the water’s edge, crosses a boardwalk and passes through mixed-grass prairie. Parking is available at the northwest and south sides of the lake.

FWS lists these three trails as open year-round and accessible. For mobility-specific questions or current surface conditions, contact the Visitor Center at 303-289-0930. (Official trail descriptions)

Wildlife Drive: leave room for slow progress

The 11-mile Wildlife Drive takes about 45–60 minutes, according to FWS. Give it extra slack if you want time to observe wildlife. Follow the directional signs, use designated parking areas and treat the posted 30 mph limit as a maximum, not a target. The optional audio tour follows the route’s mile markers.

Stay inside your vehicle when viewing bison, and throughout the one-way section through the bison enclosure. Hiking and cycling are prohibited in that section, and FWS requires at least 75 feet of separation from bison. Do not get out for a closer photograph. (Visitor safety guidance; Wildlife Drive rules)

Let weather and energy change the plan

Use Lake Mary plus the drive as the default. If everyone feels comfortable, substitute Lake Ladora; if wind, heat or fatigue makes walking unappealing, drop the walk and keep the drive, provided roads and visibility are safe.

The Visitor Center is an indoor alternative only during its opening hours. If snow, ice or severe weather makes driving unsafe—or an alert closes the route—move the refuge visit to another day rather than treating the auto tour as an all-weather backup.

Pack water, sun protection, comfortable walking shoes and a wind-resistant outer layer. Add a warm layer, hat and gloves for a cold forecast; binoculars make distant wildlife easier to watch without approaching it.

Pets cannot join walks inside the refuge; service animals are allowed under leash control. Pets on the Wildlife Drive must remain inside the vehicle and must not disturb wildlife. For a dog walk instead, use the Perimeter Trail outside the refuge boundary, keeping your dog on a leash. Parking is just before the Gateway Road entrance. Swimming, wading, drones, camping and overnight parking are prohibited. (Refuge policies)

Why it is called an arsenal

This was a weapons and chemical manufacturing site before its conversion to wildlife habitat. EPA describes extensive soil cleanup, engineered containment and groundwater treatment. The landscape’s recovery is part of the visit’s interest, but it is not permission to explore beyond public routes: access remains limited to designated roads and trails. (EPA site history; FWS access rules)