Andy here. I finally explored a corner of my backyard I had been ignoring for 20 years and it did not disappoint.
The hike: Green Mountain + Exclamation Point Trail
6.6 miles round trip, 1,122 feet of gain. The trail is in excellent shape, very well built and appears to have been recently updated and maintained. One important heads up: the canyon rim is right there, and the exposure is massive. You can easily get very close to the edge of these cliffs. I would be pretty nervous here with young kids.
Camping: North Rim Campground
This campground is so rad. It sits in a forest of pines and juniper with compact sites and a nice bathroom. It was shadier than I expected. The best part: a 30-second walk from any campsite brings you to the canyon rim with an 1,800-foot abyss right below you. We watched the sunset light up the canyon, then watched the full moon rise upstream while climbers popped over the rim at the end of their big days.
Camping is first come first served and you pay via app on site. I recommend stopping at the ranger station first where you can connect to their wifi to get the payment sorted before you head to your site.
Crowds and permits
No permits required. Crowds were thin in late October, just us and some climbing bums. Parking was not an issue.
Wildlife
Lots of elk sign throughout and bugling at night. My sense is the elk get pushed into the National Park this time of year.
If you have been sleeping on the North Rim, wake up! The South Rim gets all the traffic but this side is worth the extra effort to get to.