The railroad line that runs from San Diego to Los Angeles has seen many changes since it was originally constructed the early 1880’s. One of those changes was at the Los Penasquitos Marsh, otherwise known as Soledad Marsh. Originally, the railroad went around the marsh, passing along the hills to the north instead of going directly through as it does today. This realignment took place in 1925. The portion of the alignment crossing the marsh is still used as a utility right-of-way. The majority of the line outside the marsh has long since been redeveloped into housing.

Other than the short section of original right-of-way remaining, the only other trace of the route is through property lines. This lasting section of right-of-way represents one of the last section of intact original grade within the City of San Diego.

Remnants of the railroad include a short section of cut, some grading, and a culvert. These remnants are mostly in the area along Caminito Mar Villa, a private roadway. Use caution if you choose to explore this area.