California's wildfires wreaked havoc with travel plans, disrupting air traffic nationwide and forcing weekend gamblers on their way back from Las Vegas to find alternate routes.

Aircraft scheduled to fly to Los Angeles International Airport, San Diego's Lindbergh Field and other regional airports were grounded for varying lengths of time, FAA spokesman Paul Turk said in Washington, D.C.

Los Angeles-bound flights were delayed an average of about six hours, the FAA reported on its Web site. By late afternoon, the average delay was down to just over three hours, but the longest delays had grown to more than 16 hours.

About 100 flight cancellations were recorded by major airlines at Los Angeles International (search) between midmorning and 5 p.m. Sunday, said Nancy Castles, spokeswoman for the city airports department.

The problem began about 9 a.m. when a fire on the Marine Corps' Miramar Air Station (search) in San Diego forced evacuation of the FAA's Southern California Terminal Radar Approach Control.

The facility's functions were transferred to a center near Palmdale in the Mojave Desert that normally handles high-altitude traffic.

"The net effect is a somewhat reduced ability to take in traffic," Turk said.

By Sunday evening, FAA controllers at Los Angeles International were handling about half the normal hourly arrival rate of 70 aircraft, Castles said.

Meanwhile, closure of Interstate 15 due to the wildfires snarled traffic across the Mojave Desert as people returning from a weekend in Las Vegas had to use different routes to get home.

On the Pearblossom Highway (search), traffic crawled at 10 mph. A second route running through Lucerne Valley was bumper-to-bumper, he said.

On Highway 58 about 25 miles west of Barstow, cars backed up for seven miles during the afternoon.

"So now you have our traditional very heavy Sunday traffic trying to get home, which even on a full freeway is stop-and-go," said California Highway Patrol Sgt. Daniel Laza.

The CHP tried to coordinate traffic but lacked enough officers. The department was stretched thin trying to cover fire areas, Laza said.

One impatient motorist pulled onto a dirt road and got lost in the desert for hours. A pregnant woman in the car contacted the CHP by cell phone, but Laza said their directions weren't helpful: "We're on a bumpy dirt road and there's, like, four rockpiles."

"How am I supposed to locate those people?" he said.

The motorists later found their way back, he said.