The route is broken into two sections and cannot be used to completely pass through Pinnacles National Park.

Highway 146 has the distinction of following the San Andreas Fault line for much of its length.

[5] According to the National Park Service, Pinnacles has been administered as a wilderness area as long as that unit has been under their jurisdiction, and NPS sources contacted during research cannot recall any time when Route 146 proceeded through the park unbroken.

Except where prefixed with a letter, postmiles were measured on the road as it was in 1964, based on the alignment that existed at the time, and do not necessarily reflect current mileage.

[1] Segments that remain unconstructed or have been relinquished to local control may be omitted.