The 10-month-old boy has been identified as Elijah Rivas.
Investigators say 19-year-old Edgar Ramos, who's the boy's father, kidnapped him from his mother's house in Riverdale on Saturday night.
An Amber Alert was issued, but because Ramos' car was found in Kern County, the Amber Alert will not be visible on highway billboards. Authorities believe Ramos could be in the Fresno area or Los Angeles.
"He said he was going to come back inside in a few minutes. Three, five minutes went by, and I called him, he didn't answer," said mother Lupe Bueno. "I came out, the car was gone and my son was gone."
Bueno says she and Ramos are wrapped up in a bitter custody battle. Their next court appearance was scheduled for Wednesday.
Anyone with information on Ramos' whereabouts should call 911.