Photo Essay How Crowded Are Americaâs National Parks? See for Yourself. Americans are flocking to national parks in record numbers, in many cases leading to long lines and overcrowded facilities. Hereâs what four parks looked like over the holiday weekend. Mather Point, at Grand Canyon National Park, over the Fourth of July weekend.Credit... July 8, 2021 Largely freed from domestic travel restrictions, Americans have been flocking to national parks in record numbers this spring and summer. Several parks â including Yellowstone National Park and Grand Teton National Park â ...