A wildfire driven by gusty winds erupted in western Arizona on Wednesday and jumped the Colorado River into California, devouring more than 2 square miles of brush and prompting the evacuation of a resort and RV parks before the flames began to ease, authorities said.

The fire that began before dawn in the Havasu National Wildlife Refuge, which spans both states, threw huge waves of smoke into the air along the border before the 15- to 20-mph winds began easing in late afternoon.

The fire, which burned more than 1,400 acres of salt cedars, mesquite and river-bottom vegetation, was only 5 percent contained by nightfall, but the progress looked good, said Mike Reichling of the federal Bureau of Land Management.

"It's laying down," he said of the blaze. "The temperature's dropping, humidity's coming up a bit."

Firefighters planned to set backfires overnight to hem in the blaze, which still threatened a marina on the Arizona side of the river.

The brush fire was reported at 4:30 a.m.

Tye James, a waitress at Double Ds Roadhouse in Topock, Arizona, said she saw a wall of flames as she drove to work.  "There's just a lot of black smoke going up from around the river," she said.

No injuries were reported.

About 100 people were evacuated from Pirate's Cove, a pirate-themed family resort, and RV parks in the Mojave Desert south of Needles, California, Reichling said.

Embers slightly damaged a bar area of the Pirate's Cove restaurant before the flames were knocked down.

The cause of the fire was not known, but investigators were considering it suspicious, said Fire Chief Ted Martin of the Mohave Valley Fire District in Arizona.

The blaze is 12 miles south of Needles, a small desert city about halfway between Los Angeles and Flagstaff, Arizona.