Andy Farquhar’s outdoor adventure plans have been canceled twice this summer.

Retired teacher and attorney from Philadelphia had planned to hike for several weeks along the Pacific Crest Trail north Tahoe with a friend. But then, the second-largest wildfire in California history stampeded through the Sierra Nevada, closing 160 miles (257 kilometers) of the trail and blanketing the area in thick smoke.

He said, “I saw a satellite image of where we were going and it was all fire.”

They scrambled to find a backup plan that would keep them safe: canoeing across a vast network of lakes and swamps at the Minnesota-Canada border. That plan went poof when lightning-sparked fires forced the closure of the Boundary Waters Canoe Area Wilderness.

“We’re batting zero now,” Farquhar said.

Untold numbers of camping, fishing, hiking, horseback riding, rafting and biking adventures have been scrapped as U.S. wildfires have scorched nearly 7,900 square miles (20,460 square kilometers) this year in forests, chaparral and grasslands ravaged by drought. Most of them are located on public land in the West, which also serves as summer playgrounds.

According to Recreation.gov data, more than 24,000 of the 3.2 million camping reservations made this year have been cancelled due to wildfires. This does not include people who did not show up or those who left before the deadline.

All national forests are closed in California to prioritize fighting blazes, including the Caldor Fire near Lake Tahoe, a year-round outdoor paradise that attracts skiers, hikers, mountain bikers, boaters and paddleboarders.

The Dixie Fire has forced Farquhar’s cancellation of his plans to hike from Lake Tahoe to the Oregon border, making Lassen Volcanic National Park closed.

Arizona fires shut down several national forests, threatening Kristin Clark’s plans to travel with her family to Prescott National Forest to celebrate her mother’s 70th Birthday.

In February, she reserved the campsite. She watched as the wildfires grew and brought new closures. Before she knew it, her vacation was over.

That is Arizona’s reality. Clark stated that wildfires are occurring more often. “I was bummed. My husband was also bummed. We had been looking forward to a week in the great outdoors to sort of disconnect.