Isabel Lucas Velasco was last known to be in San Luis Obispo County on September 12.
Investigators say she has ties to both Coalinga and Visalia.
Deputies say the circumstances surrounding her disappearance are suspicious.
On Monday, San Luis Obispo County sheriff's detectives said they seized two trucks for evidence.
They are now asking for any tips related to sightings or interactions with either of the vehicles on the night of September 12, or the day of September 14 in the areas of Coalinga and Avenal.
Detectives are looking for witnesses and surveillance in the area of Highway 198, west of Coalinga, for both days.
If you have information, you're urged to contact the San Luis Obispo County Sheriff's Office.