Visitors to other U.S. national parks and historic sites were less fortunate, their travel plans spoiled by the partisan divide in Washington. The situation at the country’s 63 national parks has been less than clear-cut, however. California’s Joshua Tree National Park, named after the spiked yucca plants that grow across the park’s high-desert landscape, suffered damage during a 35-day shutdown in 2018-2019. “I worry about our national parks not being protected.”At Colorado’s Rocky Mountain National Park, scores of tourists lined a road running alongside a meadow on Thursday as a bull elk kept watch over a herd of 25 cows. “Our national parks are our common ground,” said Joann Brennan, 63, a photography professor working on a project capturing images of the parks.