A prescribed burn on Angel Island is set to resume Wednesday, Sept. 23, two weeks after fire crews paused the operation with 62 of a planned 260 acres completed.

California State Parks and the Marin County Fire Department announced the resumption in a joint news release Monday, Sept. 21. The burn, conducted in partnership with CAL FIRE, could extend through Thursday, Sept. 24, depending on conditions.

Crews began the burn Tuesday, Sept. 8, but paused after discussions with the Bay Area Air Quality Management District (BAAQMD). The release did not detail the specific reason for the pause. Bay Area air regulators had declared "Spare the Air" alerts for Wednesday, Sept. 9, and Thursday, Sept. 10, because of high ozone levels and lingering smoke from the Sept. 8 burn, which delayed the operation's continuation, KRON4 reported.

During the Sept. 8 operation, smoke drifted over a wide stretch of the East Bay during hot, nearly windless weather, reaching Richmond, Berkeley and Oakland, the San Francisco Chronicle reported. The smoke also drew complaints from East Bay residents, KRON4 reported.

Angel Island is the largest island in San Francisco Bay at one square mile and is visible from many surrounding Bay Area communities, according to the release. Smoke is expected between 9 a.m. and 6 p.m. on active burn days and may linger for up to three days after ignitions.

Agencies asked residents not to call 911 to report smoke from the island.

"We were able to burn 62 acres on the island with the fuels reduction that we've accomplished, reducing the chance of a catastrophic fire on the island," Sean Jerry, division chief of the CAL FIRE Sonoma-Lake-Napa Unit, said in the release.

Graham Groneman, division chief of the Marin County Fire Department, said crews work closely with BAAQMD to find windows that disperse smoke with the least impact on surrounding communities.

Naftali Moed, senior environmental scientist with California State Parks, said in the release, "As always, we will be doing this with our neighbors and communities in mind."

The burn targets grasslands and coastal scrub to reduce dangerous fuel loads. It is funded through Proposition 4, the $10 billion climate bond California voters approved in November 2024, which includes $1.5 billion for wildfire resilience, according to SPUR.

Whether crews can burn Wednesday depends on wildfire activity elsewhere, resource availability, weather, predicted smoke movement and fuel moisture. If conditions are unfavorable, the operation will be rescheduled. No backup date has been announced.

Angel Island State Park will stay open during the burn, but portions of the Ida Trail, Sunset Trail and the park's fire and perimeter roads will close for one to three days during and after the operation. Access to the summit of Mount Livermore will also be restricted on some burn days.

Residents can check the Angel Island State Park webpage and social media accounts for updates on the burn schedule.