The park was the countryâs fourth most-visited national park in 2020, only behind Great Smoky Mountains, Yellowstone, and Zion, welcoming 3.3 million visitors last year. That was a nearly 30 percent drop from the 4.7 million visitors who descended on the popular Colorado park in 2019, a result of the coronavirus pandemic of course. Rocky Mountain National Park was closed from March to May 2020. And when it reopened in late May, it implemented a timed entry permit system that lasted through October 12, 2020. Up to 85 percent capacity allowed in In 2021, Rocky Mountain National Park is reintroducing entry permit reservation requirements for May 28 through October 11. While still intended to limit the number of entrants this year, the park is allowing for more reservations per day in 2021 than it did last yearâapproximately 75 to 85 percent of the parkâs total parking capacity, compared to approximately 60 percent of the parkâs total parking capacity allowed in last year.