Arches NP
While I realize that you can never see "everything" in a lifetime, what's a reasonable amount of time to see the Arches, we do take short, relatively easy to moderate hikes, but not "avid" hikers. but...
Forum Discussion
For Arches itself you could do the drives and some easy hikes in 2-3 days. However, there is so much more to do in the immediate area that keeping busy for a longer period would be no problem.
