I don't normally do a lot of nature/landscape photography. But I'm going on a family vacation to Yellowstone in a couple of weeks and it will by my first trip to any US National Park. I don't know exactly what to expect other than it should be beautiful.
I have a 5Dmkii with 17-40/f4L, 70-200 f/2.8mkii, and 50 f/1.8.
I'm not sure if I need to go any wider for the landscape or any longer for the wildlife?
Have been there several times, and going again in September.
Your basic kit is pretty good, and will work well for most things you will see. You should not need anything wider for landscapes. You could use a longer lens for wildlife, a 400 would be good if you can borrow or rent one.
I DEFINATELY recommend a good tripod and ball head. The roads will be pretty busy but some night work up on Swan Lake Flats and also down in the Old Faithful area might pay off for you with some unusual shots. If you are out at night, don't forget a good flashlight and bear spray.
unless you happen to be at the right place at the right time - wild life needs longer lens - especially for the bear and wolf jams - you probably won't get any decent shots with a 70-200 even with an extender -
that said- I did have 3 opportunities with bears within 20 feet of my truck for great shots -
your landscape stuff is great -
For wildlife, you'll get bison and elk easily with the 70-200. Other wildlife will be hit or miss.
I had a 300 f/4 with a 1.4x, and got croppable views of a Grizzly (Scarface), black bear and moose. I saw wolves, but would've need an 800 to get a meaningful capture.
And yes, you should expect that it will be beautiful, and amazing.
