After a year of pining, visitors are overcrowding national parks like Yellowstone and Yosemite

Having sat at home for much of 2020 because of the pandemic, Americans are heading out in droves to national parks like Yellowstone National Park in Wyoming, and Yosemite National Park in California.

Overcrowding in recent weeks has prompted park officials to launch online reservation systems at places like Maine's Acadia National Park, Montana's Glacier National Park, Colorado's Rocky Mountain National Park and Zion Natural Park in Utah. In locations without reservation systems, parkgoers say they've discovering few to no parking spaces, 4-hour wait times to enter and increased litter along park trails. 

"This season, national parks are already bustling," the National Park Service said in a statement last month. "Like lots of places you go this year, we may not yet be able to offer the past level of service as we emerge from the ongoing coronavirus pandemic."

The number of visitors to Dead Horse Point State Park in Utah in 2021 has doubled since March 2019, according to the Wall Street Journal. Yellowstone this past Memorial Day weekend saw a 50% increase in the number of cars entering the park, compared with the same holiday weekend in pre-pandemic 2019; and Canyonlands National Park in Utah saw a 30% climb in visitors in April 2021, compared with the same month in 2019, the newspaper reported.

"We are anticipating one of our busiest summers ever in the most popular destination — national parks," National Parks Service spokesperson Jenny Anzelmo-Sarles told CBS MoneyWatch on Thursday.

While national parks appear to be rising in popularity this year, their highest usage rate ever was in 2016, with 331 million visitors in total for all 63 national parks. Anzelmo-Sarles said park service officials won't know the official 2021 visitor counts  until mid-2022. 

Seesaw effect

The pandemic has had a seesaw effect on national park usage with visitor numbers rising again after taking a sharp dip in 2020 to 237 million — from 327 million in 2019, park data show. 

"The pandemic likely was a temporary pause in a rising tide of visitors," environmental historian and Colorado State University professor Michael Childers wrote in a blog post for The Conversation, noting that visits were already exploding between 2010 and 2019. 

Park officials will have to find a way to handle the influx of visitors, while sprucing up park facilities at the same time. Last year, Congress passed the Great American Outdoors Act, which devotes $1.9 billion annually over the next five years to the maintenance and repair of national parks and public lands. 

But that's a drop in the bucket, considering the nearly $12 billion worth of bridges, tunnels, paved roads, wastewater systems, dams and parking areas that are long overdue for repairs, park officials have said.