Canyonlands and Moab are awesome in October; that and March-April are the best times to go. If your 4runner is more or less stock I'd suggest some of the following:
- Schafer switchbacks in Canyonlands. Easy road (with some exposure), but jaw-dropping scenery.
- Part of the White Rim trail. Too long to do it all unless you camp out, but the first 10-15 miles off the Schafer trail will give you a good taste of the backcountry experience.
- Long Canyon, Hurrah Pass, Chicken Corners, Gemini Bridges. Fairly short trips, not too tough, did I mention great scenery.
- Arches Nat'l Park. A couple of good backcountry roads in the Salt Valley area, and some great hiking trails on the north end at the Devils Garden. Largest collection of rock arches in the world.
Moab's a nice town to stay in - plenty of lodging and good food.
As far as getting out there, keep your eye on the weather. I-70 through Colorado is a great route, but in October it can snow and if so, it gets nasty, especially if you're not accustomed to it. If the weather is bad, consider staying south through New Mexico and coming up from there.
Weather in Moab should be good, maybe a day or so of rain, but snow and cold not likely yet, although it could be nippy in the mornings, possibly below freezing. The days warm up nicely, though.
Spend some time on the Canyonlands website (
www.nps.gov/cany), and
TrailDamage.com, the Utah section. Traildamage is the best online source of offroad trail data in the Colo/Utah/New Mexico area.
Be aware that down in the canyons cell phone coverage is pretty much non-existent, so don't plan to call for help. The routes I've listed will be fairly well traveled, so you won't get stranded for days or anything. Verizon has the best coverage out there - the rest are pretty worthless except close to town.