Evanston, WY, along the I80 corridor, relatively close-in choice. With all the national parks and other attractions related to Utah and Wyoming, it can be pricey. I've flown to Salt Lake as an alternate to Jackson WY. Heber, Utah has a steam train. Both Evanston, and Heber up over the Wasatch on I 80 east from Salt Lake City. A left at Evanston access Jackson Wy, and the two large national parks, Grand Teton, and Yellowstone.