Summer is here, it's time to head out to find your spot in the National Park System. But traffic can be a bear and leave you without a spot to park. Here's a look at 10 parks that experience some of the worst summer traffic in the system. And some solutions to consider.

Just in time for Memorial Day Weekend, Trail Ridge Road across the roof of Rocky Mountain National Park has opened. But it could close, too, in the case of a freak snowstorm, like the one that hit the area last May.

Late last summer, Rocky Mountain National Park staff began a moose research project to better understand how moose use habitat in the national park. Moose presence has been increasing annually on both the east and west sides of the park, with recent reports showing animals observed in every major drainage in the park. Research will continue this summer to better understand moose behavior.

Rocky Mountain National Park saw strong visitation in 2017, but it was down nearly 2 percent from the record year of 2016. Still, visitation to the Colorado jewel is up 40 percent from 2012 levels, according to park staff.