Snowmass welcomes boarding, whatever you want to call it, All-Terrain Boarding Dirt Boarding Mountain Boarding.
They also host the US Open Mountainboarding Nationals.
They have a short terrain park that's accessable free if you want to hike up & down. If you do, park around Lot 11 & walk over to the slopes.
You can get lift tix too, but the top of the mountain is steep as hell, so bring breaks. Uh, bring a board with breaks if you are going to the top of the mountain, or without if you are hitting the terrain park.
You can rent boards there from several places, I think it's about $20-25 for the day & includes pads.