Search for missing woman in Stirling Ranges, south of Perth

A desperate search is underway for a missing 38-year-old woman who hasn't been seen for two days.

Lorje Bautista was last seen around 4am on Tuesday morning at Bluff Knoll in the Stirling Ranges, south of Perth.

She wasn't reported missing until this afternoon.

9NEWS understands she was staying at the Stirling Range Retreat Holiday Park and staff members there called police after she failed to return to the site.

Gnowangerup Police are coordinating a search, and emergency services are also on route to begin scouring an area of Stirling Range National Park off Chester Pass Road where her car was found unoccupied in a parking lot.

It's not known whether Ms Bautista has any food or water.

Ms Bautista is described as olive skinned, approximately 157cm tall and of slim build with black hair.

She was last seen wearing a black jacket and blue jeans.