So Yosemite is the street he'd have taken BOTH to get to his warehouse from home, and to eventually get to Berkeley from home? So that means his warehouse is sort of on the way from his home to Berkeley?
So the dog went THAT way? So... Laci was (probably) being borne along by Scott when he went to his warehouse on his way to Berkeley?
Perhaps a map will put thing in a bit better prospective. The red star is near the Peterson residence. Notice Yosemite Blvd. to the south. Heading west after passing through the downtown area, notice Maze/132. The red semi/diagonal line is freeway 99. The warehouse is located near Kansas Ave. and 99.
Another route to the Bay Area = north on 99 to town of Manteca - west on 120 - south on I-5 - west on I-205.