Most National Parks have trails that are seldom used, so while the main roads can get crowded it's not too hard to find solitude in nature. You just need to get off the beaten path. One of my best experiences was taking a random hike, only to come upon a group of five moose that were grazing.

I wonder how the Parks tally the number of visitors. If I go to Yellowstone with an annual Parks pass for three consecutive days, do I count as three visitors?  If there are four people in my vehicle as I enter the Park, does the ranger tally four visitors or one?  Just wondering how they come up with the figures . . .