The county coroner says the men were 26, 35 and 38 years old but their names haven't been released.
The Beech 33 Bonanza went down Sunday afternoon in the unincorporated Newberry Springs area, about 10 miles east of Barstow.
Authorities say the plane was flying from North Las Vegas, Nev., to Corona when the pilot declared an emergency. The plane was heading to Barstow-Daggett Airport to land when it went down.
The cause of the crash is under investigation.
The plane crashed only miles from the site of a similar deadly crash. Three people were killed when a Cessna 210 heading to the Las Vegas area crashed and burned in March.