Hi Joe:
We've been to Yellowstone and the Tetons once for a two week trip; with 6 days in the Tetons and 9 days in Yellowstone
You definitely should include the Tetons if you can. The park is just south of Yellowstone and is a completely different experience.
As for Yellowstone, we were there in late September, so the crowds were slightly smaller, but some hotels in the park were already closed. Even so, we found some of the parking lots at Midway and Lower basins full by mid-day.
We spent 3 days at the Old Faithful Inn. It's pricey, but very historic and convenient to the main geyser basins; Upper, Midway and Lower basins; the names refer to their location on the Firehole River. There are several smaller geyser basins nearby that are also worth exploring. The hiking in this area is mostly level and not very strenuous. The colors in the thermal pools are amazing, and they photograph well during mid-day when the sun reaches further down into the pools.
Another spectacular geyser basin is Norris Basin. It's about a 90 minute drive from Old Faithful and about 30 minutes from the Canyon area. It's well worth spending a few hours there. We went back there twice.
Grand Prismatic Spring in the Midway geyser basin is one of the largest and most impressive thermal pools in the world. It's too big to photograph in its entirety from the boardwalk, (although you can get some great images of the bacterial mats) so ask the rangers how to get to one of the overlooks. There are two overlooks, both are a bit of a hike, but well worth the effort.
Note: Stay on the boardwalks in all the geyser basins. Scalding hot water or steam may be just below the surface.
We then spent 3 days at Canyon. The upper and lower falls at the Grand Canyon of the Yellowstone are spectacular. We also spent a lot of time in the Hayden Valley nearby. There was frost and ground fog in the valley in the early morning, which was very atmospheric. We got some nice shots of bison with a coating of frost on their fur.
Our last 3 days were spent at Mammoth Springs. The travertine terraces are unlike anything I'd ever seen and are very colorful. There were a lot of bison and elk hanging around the hotel grounds. The drive to Gardiner, Montana, just north of the park is also interesting, with mountain sheep grazing on the hillside along the roadway. Gardiner is a pretty frontier-type town, with some good restaurants. It's also the location for the famous Roosevelt entrance archway, although it's not too photogenic unless you're lucky enough to have bisons wandering about nearby.
We stayed at park lodges at all three locations, but unless you've already made reservations, you're likely out of luck; they get booked up well in advance. If that's the case, you're best bets for lodging are Gardiner in the north and the town of West Yellowstone just outside the west entrance.
West Yellowstone is about 30 minutes to Norris, 60 minutes to Canyon and about 90 minutes to the geyser basins around Old Faithful.
Gardiner is about 20 minutes to Mammoth Springs.
Note: all driving times assume no delays for construction or animal crossings. You will like experience some delays, especially in summer when the tourists will stop in the middle of the road because there's an animal nearby. We once had to wait 30 minutes in the Hayden Valley while a herd of bison stood there looking at us.
As for gear:
I used an ultrawide zoom a lot, especially around the geyser basins. There's also enough wildlife that a long telephoto zoom would be handy. I had a 90-400mm equivalent, and wished I had something a bit longer.
Be careful of the spray around the geysers; it's very corrosive and will dissolve the coating off your lenses, or eyeglasses, in short order.
Guidebooks:
One guide book that I particularly like is the National Geographic road guide to Yellowstone an the Tetons. It's very handy for finding your way around.
Amazon.com: National Geographic Yellowstone and Grand Teton National Parks Road Guide: The Essential Guide for Motorists (National Geographic Yellowstone & Grand Teton National Parks Road Guide) (9781426205972): Jeremy Schmidt, Steven Fuller: Books
It seems to be perennially out of stock at Amazon, but we picked up a copy at the gift shop at the Old Faithful Inn.
I also like the Compass Guide by Fodors...
Amazon.com: Compass American Guides: Yellowstone and Grand Teton National Parks (Full-color Travel Guide) (9780307928474): Fodor's: Books
Amazon has many more guidebooks, just search for Yellowstone in books.
If you have any specific questions, let me know and I'll try to answer them.
You'll have a great time there.....
regards
Santo
