We are a family of four with two boys of 12 and 8 wanting to visit the Moab area in August as part of a 16 day circular tour centering on Denver. The Arches and Canyonlands NPs are places we really want to see (also Rocky Mountain, Mesa Verde and Durango in Colorado) so I would like to know how long we need to do them justice, taking into consideration the heat. We will be renting a condo. We are into viewing scenery and lots of activity stuff esp biking, though again I'm not sure how much energy we'll have in 40C temperatures ! Any advice gratefully received.