Starting from the Chief Mountain Parking Area, take the trail to the left of the bathrooms at the end of the parking lot (left of the bathrooms if you are facing the bathrooms and the main road is to your right). You will quickly hike to a wooden kiosk. Read this kiosk for any pertinent information about the area such as trail warnings or wildlife warnings (you should be informed when you pick up your backcountry permit though). 

A few minutes before hitting the six mile mark, you will come to the Gable Pass Campground (will be on your right), hike past this campground and you will come to a wooden post in front of a large field with a fence. Turn right here to follow the trail to Cosley Lake Campground. If you are interested, you can also turn left here and check in at the Ranger Station.

In a mile or so you will come to a little side trail for Gros Ventre Falls on your left. I highly recommend hiking the short 0.2 miles down to the falls to take a break, fill any water bottles and stretch. When you're done, hike back out and take a left back onto the main trail. 

If you do not opt to stop at the waterfall, keep hiking straight and in a little over a mile you will arrive at Cosley Lake Campground (the side trail to the campground will be on your left), continue hiking straight. In another two miles you will arrive to the Glenns Lake Foot campground. Take a left here. Be sure to hang all food and cooking devices in the designated area before going to your campground. The two first campgrounds to your left are the only two lakefront campgrounds. There is another to the left but farther off the lake and a fourth campground to your right that is in the woods. The privy is straight ahead on the trail after arriving into camp. If you do not get a lake front campground there is a small path down to the lake to your left after passing the first two campgrounds. 

If you're lucky you will have an opportunity to see moose and elk as well as other wildlife. You may also hear wolves howling in the night!