Flying into SLC and driving down; staying in the Springdale area a few days and planning on hitting the North Rim. Looking for outdoor activity ideas; hike, float, bike in the area, Any suggestions?

Zion NP is amazing, of course, and has trails from the very easy to the strenuous and scary (Angel's Landing).  If you plan to do The Narrows, be sure to look into the logistics of that; there are guided trips with gear rental that are best arranged in advance.  It can be very hot there in the summer; when we were there, we had a miracle day in June when it was 72 degrees at 2 pm (after a cold front blew through) but plan on it being over 90.  Also, seemingly it can rain at any time (monsoon season starts in July), so be prepared to keep cameras / electronics dry in a sudden shower.

You can't really drive into the developed areas of Zion NP unless you are staying in the lodge, but the shuttles will take you to most places in the developed part of the park.  There are a couple of trail closures this summer.

FWIW, I've been to a bunch of National Parks and Zion is my favorite.  Plan to take a lot of pictures.

Also, inside the various NP's, there aren't necessarily a lot of places to eat, so you may have to have reservations if you plan to eat at a restaurant inside a park.  I have forgotten this a couple of times and had to eat gorp from the gift shops.  

dixie national forest, brian head, bryce canyon,