John Roberts and Julie Englehart, both currently 49 years old, and their daughter Brook Roberts, now 11, moved from Hesperia to Alabama, where John grew up, in 2017, according to the San Bernardino County Sheriff's Department.
After returning to California in 2019, authorities say the family was living at a Motel 6 on Cataba Road in Hesperia during the month of September and part of October.
During a phone conversation with a relative on Oct. 6, authorities say Julie said she had found a job cleaning used trailers for an unknown business somewhere in the High Desert.
She also told the relative the family was in the process of moving to an unknown location near Spring Valley Lake.
"Julie told the relative she would call the following day, however no contact was made," the department said in a news release.
The family has not been seen or heard from since.
Detectives are seeking information from anyone who may know their whereabouts, and are asking them to contact Detective Jason Schroeder at (760) 947-1500.