We would love to hear from you! Let us know if you have any suggestions or questions about Thorne or its programs.


for Main Office
1466 N. 63rd St.
Boulder, CO 80303


(303) 499-3647


(720) 292-1863



Directions to Thorne’s Education Facilities

Sombrero Marsh Environmental Education Center and Thorne Administrative Offices

1466 N. 63rd Street
Boulder, CO 80303

Directions from Arapahoe Ave. in Boulder: Turn south on 63rd Street. Ignore the “no outlet” signs. After a short distance the road will turn left/east and there will be a fence on your right beyond which you can see Sombrero Marsh. Continue driving until you see the Sombrero Marsh Environmental Education Center beyond the fence on your right. The Center is easy to identify by its wind turbine and the solar panels mounted on the roof. Please park along the fence and enter the Center on foot at the opening in the fence marked by a large Thorne Nature Experience sign.

The Kassler Center

11250 Waterton Road
Littleton, CO 80125

Directions from C470 in Ken Caryl/Columbine: Exit C470 onto S. Wadsworth Blvd./Highway 121, which becomes S. Platte Canyon Rd. Drive south past the US Army Corps of Engineers Visitor Center, the entrance to Chatfield State Park, and Chatfield Reservoir. After 4.3 miles, bear left following signs for Waterton Canyon and Denver Water’s Kassler Center. Go another .3 miles and turn right into the Kassler Center property. Thorne programs are operated out of the first building on the right. PLEASE NOTE: Only drop-off and pick-up parking is allowed at the Kassler Center. If you plan to visit the Center for a longer period of time or take a hike on nearby trails, we recommend parking in the lot that is across the street and to the North.