Tetons from Idaho

Grand Tetons National Park is mainly on the east side of the Tetons. But what about the west side? Why is there no national or state park on the west side? I did a side trip, going all the way from Lewis Campground to West Yellowstone, taking the scenic route through Jackson, Wyoming and then across Teton Pass into Idaho and then north through the Teton Valley:

The furtherest you can drive into the Grand Tetons in a conventional vehicle on west side is the Grand Targhee Resort. You quickly learn what the problem is with Grand Tetons on the west: the big mountains are blocked by smaller mountains, and there's no big lakes that are easily accessible. Here are some images taken from the road to the resort:

The drive to West Yellowstone led one to some dry agricultural areas: