CORONA (CBSLA) – Firefighters continue to battle a 250-acre fire which sparked Thursday on the edge of the Cleveland National Forest in Corona, forcing hundreds of people to evacuate. (CBS2) The Skyline Fire broke out in the area of Skyline Drive and Burrero Way at around 3:10 p.m. Thursday near a popular hiking spot. As of 9 a.m. Friday, it remained only 5 percent contained, according to CAL Fire. Steep terrain and hot temperatures are creating challenges for firefighters. Overnight Thursday, a decrease in wind and an uptick in humidity offered some respite to crews. As of Friday morning, more than 1,500 structures remain threatened, CAL Fire reported. However, no homes have been damaged or destroyed and there were no injuries. Evacuation orders were lifted for several neighborhoods Thursday evening. About 50 homes remained under mandatory evacuation orders in the Maybeth Canyon and Orchard Glen neighborhoods Friday, including the 1400 block of Burrero Way, the 1400 block of Burnett Circle, the 1400 block of Folson Circle, the 1400 block of Brannon Circle, the 3500 block of Rawley Street and the 1400 block of Gareth Circle. Foothill Parkway is closed from Lincoln Avenue to Paseo Grande. About 300 firefighters with CAL Fire, the Corona Fire Department and the U.S. Forest Service are battling the blaze. A Red Cross evacuation shelter at Corona High School was closed due to a lack of demand, the city reported. The cause of the fire is unknown.