The park, established in 1989,[1] stretches for 55 miles (89 km)[2] from the mouth of San Dieguito Lagoon (a lagoon between Solana Beach and Del Mar) to the Volcan Mountain Wilderness Preserve close to Julian, following the San Dieguito River.

The park contains the Coast to Crest Trail with the planned length of 70 miles (110 km).

[1][3] Open space within the park is a home to multiple species, including 230 birds.

Coastal sage scrub habitat includes least Bell's vireo, cactus wren, California gnatcatcher and San Diego horned lizard.

[1] A restoration project in the San Dieguito Lagoon was completed in 2011 at the cost of 86 million dollars.