In the Zion area there is some INCREDIBLE mountain biking. Gooseberry Mesa, JEM trail, and Brianhead (if the shuttle is open) are all freakin' phenomenal. Also some incredible hikes/canyoneering in Zion. Keyhole canyon is short and super-fun (you'll need to rent a drysuit)- has a few short raps into deep pools. Subway is a great day-hike with one rap that is optional (we didn't use it- seemed like an easy and safe down-climb) . The Narrows is an uber-classic hike, though you need to go for awhile (at least to Orderville Canyon) to distance yourself from the tourons. Have a great time!