Three fires had burned more than 40,000 acres in Santa Barbara and San Luis Obispo counties by June 10, triggering air quality warnings and shutting down major traffic arteries.

Smoke from the Alamo fire, which had burned nearly 29,000 acres near the Twitchell Reservoir and was 15 percent contained as of 1:35 p.m., drifted into both San Luis Obispo and Santa Barbara counties.

Around 50 miles to the south, the Whittier fire was 5 percent contained at more than 10,800 acres, closing down Highway 154 from Santa Barbara to Highway 246.

More than 3,500 cars detoured through the Santa Ynez Valley over the weekend, said Tracy Beard, executive director of the Solvang Chamber of Commerce. Businesses remained busy until Monday, when air quality alerts kept residents and visitors alike indoors.

To the north, residents were encouraged to evacuate near Santa Margarita, and the Stone fire was around 40 percent contained on Huer Huero Road.

Causes for the three fires were still under investigation and several others were in varying levels of containment statewide.

• Contact Marissa Nall at mnall@pacbiztimes.com.