Here are two absolutely phenomenal resources for destinations in the Tetons:
Grand Teton National Park - Grand Teton Park - Grand Teton Hikes and, particularly,
Best of the Tetons, Area Info & Photography. This page provides an index of the author/photographer’s featured posts on the latter website:
Archived Feature Posts. You will be a little early to see much fall color, but he has great articles on fall-foliage destinations in the Tetons, such as the following:
Fall in the Tetons: Tips for viewing and photographing the premiere season!
Fall at Oxbow Bend
Fall in the Snake River Canyon: (Note: The Snake River Canyon is one of those rare Rocky Mountain destinations where you have a good concentration of mountain maples, in addition to aspen, cottonwoods and willows, so you have an unusually varied color palette.
If I Had Only One Day in the Tetons
Incidentally, I understand the allure of Yellowstone; it has an assemblage of wildlife unrivaled in the lower 48 and a concentration of thermal features unsurpassed in the world. If, however, you most highly value rugged alpine topography, it does not hold a candle to Glacier National Park, the Tetons, Beartooths, Wind River Range (Wyoming), Sawtooth Mountains (Idaho), Maroon Bells (Colorado), or the San Juan Mountains, particularly the Sneffels Range, in southwestern Colorado. Incidentally, the San Juans are far more spectacular than Rocky Mountain National Park and much less heavily visited. This image (
Sneffels Range Autumn | San Juan Mountains, Colorado) will give you an idea of what the latter range has to offer.
The Wind Rivers are not far to the southeast of the Tetons and comprise some of the most remote terrain anywhere in the country. The Green River Lakes area is an iconic and historic destination in the northern portion of that range. See
Green River Lakes Campground and trails, Wyoming.
In the Northern Rockies, inclement weather destinations are always a good idea to have in your back pocket. Two excellent ones are the Buffalo Bill Center of the West (
Buffalo Bill Center of the West | Museum in Cody, Wyoming) in Cody and the Museum of the Mountain Man in Pinedale (
Museum of the Mountain Man).
P.S. If you ever want to specifically target peak fall color in the Northern Rockies, generally the last week of September and first week in October are best.