A wildfire that broke out Thursday in the Santa Ana River bottom near downtown Riverside blackened 50 acres and spawned multiple spot fires amid high winds before being partially contained.

The blaze was reported about 11:10 a.m. on the perimeter of a Boy Scout camp, in the area of Mission Inn Boulevard and Indian Hill Road.

According to the Riverside Fire Department, flames quickly spread into deep brush along the dry river bottom, propelled southward by 30 mph winds.

As of 4 p.m., the fire was 50 percent contained, and crews remained busy knocking down small spot fires ringing the main burn area.

Evacuation orders were issued for residents on the north side of Mission Inn, on the south side, around Mount Rubidoux and in places along Arfon Way, Glenwood Drive, Loring Drive, Mount Rubidoux Drive, Redwood Drive and several other side streets abutting Mount Rubidoux Park.

All evacuations were lifted as of about 6:30 p.m.

A temporary evacuation center was established at the Dale Senior Center, 3936 Chestnut St., next to White Park. Some residents had also displaced to Bonaminio Park on Tequesquite Avenue, where fire crews were staging.

Arson investigators were called to the point where the fire began, but there was still no word on what triggered it.

A property on Redwood Drive was reportedly damaged by flames, but the extent of the loss was not immediately known. The backyard of a home in the 4600 block of Ninth Street caught fire, but crews rapidly deployed and kept the flames at bay.

A woman residing in the 4000 block of Redwood Drive, just off of Glenwood, crawled onto the roof of her home in an apparent attempt to douse embers and fell. She was taken to Riverside Community Hospital for treatment of a possible broken leg, according to reports from the scene.

Embers hurled skyward by the intense Santa Ana winds lit on palm trees along Arfon, Glenwood, Mount Rubidoux, Mission Inn, Pine Street and Redwood, sparking isolated fires with which individual engine crews had to contend. Riverside police officers cordoned off streets to assist firefighters and ensure public safety.

The Mission Inn Avenue bridge connecting Jurupa Valley and Riverside was shut down.

Engine and truck companies from Riverside County, Cal Fire, Corona, the March Air Reserve Base and other agencies assisted with battling the wind-whipped fire. By 4 p.m., some personnel were being released.

Several Cal Fire water-dropping helicopters and air tankers made runs on the blaze, mostly on the north side of Mount Rubidoux, in the vicinity of Carlson Dog Park. The choppers were using nearby Lake Evans at Fairmount Park to take on water.

All aircraft were called off and headed back to their respective bases as nightfall approached.