Hikers, campers, bird-watchers and others who love outdoor recreation will be barred indefinitely from one of their most prized preserves: the Coronado National Forest.
Officials announced Monday that the entire 2 million-acre forest will be closed at noon Thursday because of extreme fire danger.
"The closure will remain in effect until significant moisture arrives," said Jim Upchurch, supervisor of the forest encompassing mountain ranges across Southern Arizona.
"We recognize the impact this closure will have," Upchurch said. "But these are unprecedented fire conditions."
The closure includes popular Sabino Canyon northeast of Tucson.
The only exception will be that the Catalina Highway to Summerhaven in the Catalina Mountains north of Tucson will remain open to residents, business operators and the public during daylight hours. But no stops may be made at overlooks, trails or other sites along the way to Summerhaven. The road will be closed at night.
Violators could face fines of up to $5,000, imprisonment of up to six months or both, said Heidi Schewel, a spokeswoman for the forest. She said the last time the forest was closed because of fire danger was about eight years ago.
Parts of Saguaro National Park also will be closed starting Thursday, park Superintendent Darla Sidles said.
She said all high-country trails and sites in the park's district east of Tucson will be closed, but the eight-mile-loop drive in the district will remain open. The district of the park west of Tucson is in desert mountain terrain and will remain open, Sidles said.
Sites affected by the forest closure include several Scout and religious camps in the Catalinas.
"Hundreds and hundreds of girls are going to be very disappointed to not be camping up there, but we support the decision to close the forest," said Debbie Rich, chief executive officer of the Girl Scouts of Southern Arizona - Sahuaro.
She said 490 campers, ranging in age from 7 to 17, were registered for camping this summer at the Girl Scout camp.
"We hope to reschedule the camps that were slated for June and hold them in July," Rich said. "But our camp staff (of about 20 counselors and junior counselors) won't have work for the month of June."
Other groups with camps in Southern Arizona - as well as hikers, rock climbers and casual forest visitors - will also have to cancel outings or travel to distant sites in other forests.
Officials said they saw little choice but to close the forest in view of what Upchurch described as "an unprecedented fire season."
Noting large fires such as the Horseshoe 2 Fire raging in the Chiricahua Mountains and the Murphy Fire scorching the landscape west of Tubac, Upchurch said firefighters are reporting fire behavior "as extreme as they've ever seen it."
He said officials decided a closure was necessary because "the great majority, if not all the fires, on the Coronado National Forest (this year) have been human-caused. Causes of fires include ricocheting bullets, campfires, welding equipment and possibly ignition by smugglers or illegal immigrants," Upchurch said.
He acknowledged that enforcement of the closure will be a challenge.
"With 2 million acres of national forest, we can't be everywhere," he said. "But we will have enforcement officers out and about."
Kristy Lund, acting fire-management officer for the forest, said that "it's a real worst-case scenario for us."
Even the closure can't prevent fires if dry lightning storms move into the area. "With no rain," Lund said, "virtually every lightning strike will start a fire."
Contact reporter Doug Kreutz at email@example.com or at 573-4192.