What veggies can be started in the fall, in Wyoming?

Most all perennials are great to be planted in the fall, as far as flowers and citrus trees go, but that's not answering your question.

Winter vegetables like cabbage, cauliflower, leeks, brussell sprout, escarole, garlic, kale, even parsley keep well in wintertime. For the fall of course beets. All of it can be harvested at least by January. Little pansies are also frost hardy and very cute in boxes or borders.

Time your planting late enough so that they don't have time to go to seed before the cold November weather tells them to slow their growth.

Hope this helps. Good luck.