I was in Yellowstone a few years ago. We went in early August to make sure the snow was gone, the roads were open and the trails dried out. It was, they were and they were.

There's a possibility I'll be going back with my daughter and granddaughter next summer but a bit earlier.

Any idea what's the earliest we'd be sure of summer conditions?

We were there June 14-18 2009. The roads didn't fully open until the day we arrived. During a heavy snow year, I would imagine a bit later. We had planned on driving Beartooth HWY, but it hadn't opened that year. We really did very little hiking, so I can't say for sure on that. Higher elevations would dry out later.

We are going to Mount Rushmore next year for sure. I do have reservations for Yellowstone too, but not positive we will do that portion or not. We will be in Rushmore Mid-June and then Yellowstone that last of June. I am going to attempt The Beartooth again on this trip. I should say, that I wasn't able to get exactly(still pretty good though) what I wanted in YS, so you should get your reservations ASAP.

I think you are likely to see more wildlife and more babies, the earlier you go though. I still want to soak in Boiling River and Swim in Firehole River. The rivers are usually to full and flowing to fast until later, so very unlikely I would get to do that next year. Plus, it isn't as crowded in June as it is July or August and not likely to be hot. Trade-offs anyway you look at it.

Actually, I'm not thinking of that early.

I was there in early August last time. Now there are some things on the schedule for August so it might be around the 3rd week of July. That should be fine.