# California State Route 154

State Route 154 (SR 154) (also known as the Chumash Highway or unofficially as San Marcos Pass Road after the signage) is a state highway in the U.S. state of California that runs from Los Olivos to Santa Barbara, crossing the San Marcos Pass in the Santa Ynez Mountains. Before U.S. Route 101 was built through the Gaviota Pass, SR 154 was the main throughway to Santa Barbara and the tri city area including use as a stagecoach route in early years. After being replaced by US 101 as the primary route between the Santa Ynez Valley and Santa Barbara, SR 154 now serves as a scenic bypass.

## Route description

It is a two-lane road with some passing lanes, with the highest altitude being 2000 ft. It rivals US 101 for traffic, but it goes through the Los Padres National Forest and the San Marcos Pass. It starts in Los Olivos as a spur from US 101, goes through the town, and then the end of SR 246 at Santa Ynez. It then reaches Lake Cachuma and passes through the Los Padres National Forest, and across the Cold Spring Canyon Arch Bridge, where Cold Spring Tavern is on Stagecoach Road which passes below the bridge. Nearby it crosses Camino Cielo Road to the east and west, then the intersection of Painted Cave Road and Old San Marcos Road before descending to Santa Barbara. It then briefly becomes a super-two freeway and passes an interchange for SR 192 (named Foothill Road to the east and Cathedral Oaks Road to the west of SR 154), before stopping at Calle Real and a southbound onramp to US 101 and ending at the point where State Street to the east becomes Hollister Avenue to the west.
SR 154 is part of the California Freeway and Expressway System, and a portion in Santa Barbara is part of the National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the Federal Highway Administration. SR 154 is eligible for the State Scenic Highway System, and is officially designated as a scenic highway by the California Department of Transportation, meaning that it is a substantial section of highway passing through a "memorable landscape" with no "visual intrusions", where the potential designation has gained popular favor with the community.

## History

The highway from Santa Barbara through San Marcos Pass to what was Route 2 was added to the state highway system in 1931. The route renumbered to SR 154 by the 1964 state highway renumbering.
On the short super-two freeway section of SR 154, the interchange with SR 192 is numbered as exit 32, despite the route not being listed on Caltrans' Cal-NExUS webpage.

## Major intersections

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. R reflects a realignment in the route since then, M indicates a second realignment, L refers to an overlap due to a correction or change, and T indicates postmiles classified as temporary (for a full list of prefixes, see California postmile § Official postmile definitions). Segments that remain unconstructed or have been relinquished to local control may be omitted. The entire route is in Santa Barbara County.
| Location | Postmile | Exit | Destinations | Notes |
| Zaca Station | R0.00 | | US 101 – Santa Maria, Santa Barbara | Interchange; west end of SR 154; US 101 exit 146 |
| Santa Ynez | R8.11 | | SR 246 west / Armour Ranch Road – Santa Ynez, Solvang, Buellton | Roundabout |
| ​ | 22.96 | Cold Spring Canyon Arch Bridge | Cold Spring Canyon Arch Bridge | Cold Spring Canyon Arch Bridge |
| ​ | 24.40 | San Marcos Pass, elevation 2,181 feet (665 m) | San Marcos Pass, elevation 2,181 feet (665 m) | San Marcos Pass, elevation 2,181 feet (665 m) |
| ​ | | West end of freeway | West end of freeway | West end of freeway |
| ​ | R31.55 | 32 | SR 192 east (Foothill Road) / Cathedral Oaks Road | |
| ​ | | East end of freeway | East end of freeway | East end of freeway |
| Santa Barbara | 32.28 | | US 101 (SR 1) | Interchange; east end of SR 154; US 101 exit 101B |
| Santa Barbara | 32.28 | | State Street | Continuation beyond US 101 |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi |||||