Deputies with the San Bernardino County Sheriff's Department responded to the school grounds and cleared all of the buildings.
Following the search, sheriff's officials confirmed that no suspect was located, there were no injuries, and that the initial report about an armed student turned out not to be credible. The lockdown was lifted shortly thereafter.
Sheriff's officials said they initially received a call reporting a threat about a student with a gun on campus at around 12:30 p.m. At that time, students were at lunch. When deputies arrived on scene, students were moved indoors for safety until the campus was cleared, authorities said.
Video from inside the school's gym shows armed deputies going through the area during the lockdown.
Upon investigation, authorities learned that the same phone number that called in the report to the sheriff's department on Friday has been connected to a previous hoax incident at another high school in San Bernardino County, authorities said.
WATCH | Video shows armed deputies inside Apple Valley HS gym during lockdown
Apple Valley High School lockdown: Video shows armed deputies inside school gym