Yellowstone National Park is deservedly one of the world's great tourist destinations, but if you limit your visit to the confines of Yellowstone National Park you will miss a lot of interesting sights in the nearby region. These include:
First, arrival by air. A lot of tourists heading to Yellowstone fly into Salt Lake City, but an SLC rt flight will "cost" you two days of time on the road for going to Yellowstone and back. Bozeman, MT, on the other hand is less than a two hours drive from Yellowstone's west or north entrances. Billings is a little further away, but if you are renting a car, you get to go over the spectacular Beartooth Highway from Billings (via Red Lodge) to get to Yellowstone. Idaho Falls is also worth a look because it lends itself to nice loop drive-- airport to West Yellowstone to Grand Teton National Park to Jackson, WY, over the Teton Pass, and back to Idaho Falls.
There are two main sources of volcanoes, plate tectonics and hot spots. Most volcanoes--- the ring of fire, Mt St Helens, The Cascade Range,-- are the product of plate tectonics. Volcanoes erupt at the intersection of plates where one plate slides under another, creating volcanoes in two ways: 1] the fiction of the descending rock creates heat that helps make magma and 2] the crack in the Earth's surface at the plate boundary creates a path for magma formed deep underground to rise to the surface. A Hot Spot works differently. A Hot Spot is a place on the Earth's surface not at plate boundaries where a chamber of deep Earth magma reaches near enough to the surface to break out in volcanic action-- lava flows(a horizontal volcano) or volcanoes (a vertical lava flow). Yellowstone, Hawaii, and Iceland are examples. Plate tectonic volcanoes are mostly stationary, created at stable plate boundaries, but Hot Spots appear to move across the surface of the Earth. In reality. the Hot Spots are stationary while the surface of the overlying plate moves across the hot spot. The Yellowstone Hot Spot first appeared about 16,000,000 years ago near the Idaho-Nevada-Oregon border. It then moved northeast to Yellowstone, arriving about 2,000,000 years ago. While making the move, vast lava fields covered the eastern half of the Snake River Plain. The 750,000 acres Craters of the Moon National Monument covers one of the more interesting areas. Astronauts going to the Moon come here to practice walking on the Moon's surface. The Snake River lava fields are far bigger than Carter of the Moon and also include the Idaho National Laboratory, which among other things, is home to the first Atomic Power plant (open to the public); the town of Arco, home to the first atomic powered lighting; and a very secret US Navy base, 700 miles from the nearest ocean.
The altitude of the Snake River Valley lava beds is about 5,000 ft. The altitude of most of Yellowstone National Park is around 8,000 ft, in a caldera ringed by 10,000 ft high mountains. Although both the lava fields and the volcano were created by the Yellowstone Hot Spot, there is a big difference. The lava fields are a lava flow, Yellowstone is a volcano caldera.
I think that Yellowstone cannot be fully appreciated without a visit to the Snake River lava fields.
US Rt 212 is the only road in Yellowstone National Park that is open 12 months a year. East of the park, it splits into two grand scenic mountain drives, 1] Beartooth Highway, US Rt 212 (to Red Lodge MT)), and 2] the Chief Joseph Scenic Highway, WY Rt 296 (to Cody, WY). If you really want to get away from it all, the vast and rugged Absoroka Mtns are just to the north of US Rt 212.
This is the home where Buffalo Bill roamed. Cody, as in Buffalo Bill Cody, has a large Buffalo Bill entertainment complex, daily rodeos in season, a museum of Buffalo Bill stuff, and the Irma Hotel, built and operated by Buffalo Bill, named after his daughter Irma. Its a necessary stop to see the bar, a gift from Queen Victoria to Buffalo Bill. Continuing east on scenic US Rt 14, another of Buffalo Bill's hotels is over the next mountain range in the town of Sheridan, WY. US Rt 14 splits on the way to Sheridan. I think Rt 14A is a little more scenic than Rt 14, but either is a fine mountain drive.
Its 8 miles from the South Entrance to Grand Teton National Park by the J D Rockefeller Jr Parkway, and it is absolutely essential that if you going to visit both National Parks, you must go from Yellowstone National Park to Grand Teton. Going this way, on a scale of 1-10, the scenery is 12. Going the other way, 3 maybe 4.
Grand Teton National Park highlights: the lobby terrace at the Jackson Lake Lodge; Oxbow view paint; Mt Moran pull over; Jenny Lake.
Packaged tours and do it yourselves usually include the town of Jackson, WY in their visit to Grand Teton, so I'll clear up the lexicon. The early explorers of the west had a bunch of different names for mountain valleys. There was some geographic basis to these, with a gully or gulch being really narrow and not very deep. Valleys were wider and deeper. Canyons had very high walls but were narrow than valleys. Parks and Holes were really big valleys. Thus, Jackson Hole is the name of the really big mountain valley you enter when traveling south from Yellowstone National Park to Grand Teton Yellowstone National Park. Jackson is the name of the big tourist town in Jackson Hole. Jackson Hole is also the name of a famous ski resort located on the mountains on the west side of Jackson Hole.
If you don't want to look like a tourist, the star of Grand Teton National Park, the Grand Teton, is know to the locals as "the Grand".
The Absoroka Mountains, perhaps the most rugged mountain chain in the lower 48 states, separates Yellowstone National Park from the Great Plains. On the edge of the Plains, Livingston is an attractive somewhat preserved Old West town. Greycliff Prairie Dog Town State Park is east of Livingston just off I-90. Based on several visits, its safe to say that if you stop, you will see Prairie dogs. The Tippet Rise Outdoor Sculpture Garden is further east off I-90 near Columbus.
The town of Big Timber, west of Prairie Dog Town, has a Town Pump gas station on US Rt 191 whose gas prices are way lower than you will pay in or near Yellowstone National Park. Rt 191 connects Yellowstone National Park and Glacier National Park. The Town Pump sells regional souvenirs from both areas at lower prices than you will pay in the vicinity of the parks. Especially recommended: Huckleberry syrup for pancakes etc, or on pork chops (add thyme). There are several Town Pumps in Big Timber. Go to the one furthest north from I-90 on Rt 191.
Guided tour of Sapelo Island five miles offshore from the Georgia Coast. Includes roundtrip ferry ride to the Island, the University of Georgia's Marine Institute, R. J. Reynolds Mansion, historic, Sapelo Island Lighthouse, beautiful unspoiled and undeveloped Atlantic Ocean beach, and African-American community of slave descendants.