Kempker, who lives in Concord, was reported missing on Tuesday.
Missing person flyers have been posted in the area along Highway 160. Kempker's car was found by Sacramento County Sheriff's deputies on Wednesday along the highway in a remote area.
Kempker's loved ones describe him as an avid outdoorsman, who loved fishing.
The public is encouraged to call 925-603-5836 if anyone has information regarding Kempker's whereabouts.