As firefighters fought the blaze at Bridal Veil Falls for a fourth straight day, the U.S. Forest Service said it expects the fire to be contained by Wednesday night.

Over the weekend, Forest Service officials estimated that the fire had burned about 40 acres, but that estimate was upped to 240 acres after officials were able to use GPS technology to map the burned area. Forest Service spokeswoman Kim Osborn said the area's steep terrain had made it difficult to determine how much land had been burned.

Osborn said the fire was about 20 percent contained.

"The rain helped some, but we still have hot spots," Osborn said.

Two crews consisting of 45 firefighters from Salt Lake County and the Bureau of Land Management battled the fire on Monday, while three helicopters pulled water from the Provo River to dump on the blaze. One of the helicopters is a "sky crane" that can dump 1,500 gallons of water at once.

Officials were still investigating the cause of the blaze. The Forest Service said the fire was human caused, but Osborn said fire officials were still investigating whether it was accidental or arson.

The fire began late Thursday night at the abandoned Bridal Veil Falls restaurant, and fire officials were able to extinguish the flames before they spread to the surrounding area. But thunderstorms on Friday night and Saturday brought gusty winds, which blew hot embers into the trees and spread the fire.

• Jeremy Duda can be reached at 344-2561 or jduda@heraldextra.com.