With swaths of California on fire — from theCaldor Firenear Tahoe to theDixie Firestill burning in Northern California — theUnited States Forest Servicetoday announced it is closing all of California's national forests to the public starting Tuesday, Aug. 31 at 11:59 p.m. The closure is in place until Sept. 17 but could be extended.

“We do not take this decision lightly but this is the best choice for public safety,” said Regional Forester Jennifer Eberlien in a news release. “It is especially hard with the approaching Labor Day weekend, when so many people enjoy our national forests.”

Also closed: The Pacific Crest Trail throughout all the affected forests. The Pacific Crest Trail Assn. on Mondayadvised all hikersin those areas: "If you are out there now, it’s time to start walking out to the trailhead."

The order impacts 19 forests that cover approximately 20 million acres. (It does not affect the Humboldt-Toiyabe National Forest, which is managed by a different division of the Forest Service):

1. Angeles

2. Cleveland

3. Eldorado

4. Inyo

5. Klamath

6. Lassen

7. Lake Tahoe Basin Management Unit

8. Los Padres

9. Mendocino

10. Modoc

11. Plumas

12. Rogue River-Siskiyou

13. Sequoia

14. San Bernardino

15. Shasta-Trinity

16. Sierra

17. Six Rivers

18. Stanislaus

19. Tahoe

Four of these national forests —Angeles,Cleveland,Los PadresandSan Bernardino— are in Southern California. All have been considered under "very high" or "extreme" fire danger for weeks.

The Forest Service says the closure order will decrease the potential for new fire starts at a time when the West Coast's firefighting resources are stretched thin. The closure order also stated, "By temporarily reducing the numbers of people on national forests, we hope to minimize the likelihood that visitors could become entrapped" in these forests if a fire breaks out.

The closures were first reported by theSacramento Bee.

The move isn't totally unexpected. Earlier this month, the U.S. Forest Service's Pacific Southwest division, which covers California, Hawaii and parts of the Pacific Islands, announced it wasclosing all nine national forests in Northern Californiafrom Aug. 22 through Sep. 6.

This order does not affect camping in state parks such as Anza-Borrego Desert and El Capitan Beach or in national parks such as Yosemite.