Steamboat has wonderful hiking, botanical garden, biking and more! The visitor's guide is wonderful place to start planning your trip.
Fish Creek Falls - easy hike down to the falls and back. For a longer adventure, cross the river and keep on going - a long hike up will take you to a second smaller falls and after about 6 miles will end at a 'lake' - really a reservoir. The hike is challenging and beautiful, but the lake at the top is not as pretty as we expected.
Mad Creek - pretty, fairly easy hike up to an old barn.
Hahn's Peak - a bit hard to find the start of the trail, but stop at the Steamboat Lake Visitor's Center for good directions. The trail at the top is along a ridge, so not for those afraid of heights. But if you make it to the top, the view is incredible!
Mosquito Lake - a bit of a drive towards the Flat Tops, but a gorgeous lake! Keep going past the lake for a very challenging hike over the aptly named Devil's Causeway.