Marion Lake Trail is a 13.4 mile loop trail located near Moose, WY that features a lake and is rated as difficult. The trail is primarily used for hiking, camping, and backpacking and is accessible from July until September.
Grand Teton National Park P.O. Drawer 170 Moose, WY 83012-0170 Information (307) 739-3300 More information: http://www.nps.gov/grte/contacts.htm
Even though the tram cuts out 6.6 miles, it's still a very strenous hike with a lot of elevation changes. Marion lake is a beautiful high elevation lake tucked up next to a limestone wall. The wildflowers surounding the lake are especially nice here.
This loop has a lot of junctions in it. So, just use a little bit of caution.