TUCSON, ARIZ. ? Officials urged residents and guests of a desert resort to evacuate an exclusive enclave on the city’s northern fringe Sunday after a wildfire sped downhill, surprising firefighters and threatening about 200 homes.

The area, called Ventana Canyon, is a high desert enclave in the foothills of the Santa Catalina Mountains. It includes upscale homes and the 400-room Loews Ventana Canyon Resort, said George Heaney, a bureau chief with the Pima County Sheriff’s Department.

The voluntary evacuation notice of about 200 homes and the resort came after strong winds pushed the fire downhill faster than expected, fire officials said.

Smoke roiled in ravines along the face of the mountains late Sunday afternoon. Helicopters dropped water as the flames moved downhill through rocky desert terrain.

Sharon Swofford, loading bags into a car with her husband, said resort guests were set up with rooms at another Tucson resort.

“We called last week about canceling. They said they weren’t really concerned. When we checked in Friday night, they said not to worry,” said Swofford, of Washington D.C. “It was fun watching the helicopters though.”

Sheriff’s deputies knocked on doors to urge Ventana Canyon residents to evacuate.

About half of those contacted said they would leave, said Sgt. Jim Ogden of the Pima County Sheriff’s Department. A hotel spokeswoman didn’t return a message seeking the number of guests on Sunday.

The fire, which started June 17 and has burned at least 70,000 acres, skirted fire lines last week and burned six cabins between Friday night and early Saturday.

Lines created by burnouts, clearing brush and thinning trees continued to hold Sunday around dozens of other homes and cabins, several youth camps, an observatory and communications towers operated by organizations including the Federal Aviation Administration.

But as the situation on top of the mountain looked better, the fire kept creeping down the mountain face toward the foothills. Officials said they could snuff it with helicopter water drops and backburns and that thin desert vegetation in the foothills would make the fire easy to fight if it approached homes.

The fire also was about a half-mile from the visitor center at Sabino Canyon, a popular recreation area that was closed because of the fire.

The human-caused fire destroyed 317 homes last month in and around the vacation hamlet of Summerhaven.