I'll try this again. YNP is big--very big. Traffic is slow, with speed limits of 45 mph tops and as low as 25 mph in lots of places. There is considerable traffic, wildlife on the road and visitors--photographers!!--stopped by the side of the road to view/photograph the wildlife and other sites. We stayed at the Yellowstone Lake Hotel when we were there at the end of May last year, and found the road between Canyon and Tower Junction was still under 10+ feet of snow, so the road was closed. There was work ongoing on the road between Canyon and Norris, so there were delays. Getting to the wildlife-rich Lamar Valley took about two hours, if I remember correctly. In short, even when we had the best of conditions, it took a lot longer than we imagined to get from point A to point B. I'd go again in an absolute heartbeat, but I'll be better prepared for the transit time.

West Thumb Basin, Lake Yellowstone and Fishing Bridge were great for sunrise shots.

You'll love it and with patience, have a wonderful time.

Check all the entry points for Yellowstone.... NOW would be good.

Three times in the past few years, I have visited Yellowstone with two of those times finding at least one entrance/exit I wanted to use closed for some sort of highway or bridge repair. You can't believe how long it takes to use the highways around the outside of Yellowstone to get from one side of the park to another side of the park.

I lost over half a day on one such go back and around. In that case, I had to backtrack about 50 miles before going around since the posted close was fairly close to the park entrance.

Can't speak to the same potential problems at the Tetons.

Here is a link to a discussion about this on the Adobe forums. Somewhere in the middle is a link to J Kost's video tutorial. https://forums.adobe.com/message/5257734. It is imperative to do this right or you may face many days of agony trying to unravel the problems. I have done it right 4 times and wrong once. It is worthwhile to study up and do it right.

On a mac, you don't have to worry about all that B,C,D drive stuff. Give your drive a name specific to itself. Mine are simply named by brand and order bought (LaCie 1, WD3, Buffalo1) because at some point I might use them for some other purpose and don't want them named Photos or something like that.

I typically have 2 drives in my systems. A C:\ and a D:\. The C:\ drive is intended for installation of all software. Almost every software title that manipulates data will allow you to configure where that data is, and for me, it's on the D:\ drive.

One can use an external drive as their D:\ (data) drive, but it should not be construed as a "backup". Whatever is there is what I call 'active' data, and it should be backed up to another appliance.

With the advent of USB 3.0 specification, these external units can move along quite nicely. I don't think speed will be a big issue.