# California State Route 66

State Route 66 (SR 66) is a state highway in the U.S. state of California that runs along a section of old U.S. Route 66 in Los Angeles and San Bernardino counties. It goes from State Route 210 in La Verne east to Interstate 215 in San Bernardino, passing through Claremont, Upland, Rancho Cucamonga, Fontana and Rialto along Foothill Boulevard. In San Bernardino, it is the part of Fifth Street west of H Street (at the Interstate 215 interchange).

## Route description

The route begins as Foothill Boulevard at the interchange with SR 210 in the city of La Verne. SR 66 heads southeast for a few miles before entering Pomona and turning due east. The highway continues into the city of Claremont, passing by Claremont Colleges, before crossing into Upland, San Bernardino County.
In Upland, SR 66 passes by Cable Airport to the south, continuing due east. The highway intersects SR 83 before entering Rancho Cucamonga, where state maintenance of SR 66 currently ends. Foothill Boulevard continues east through Rancho Cucamonga through an interchange with I-15 before entering Fontana, and passing well north of the California Speedway. Foothill Boulevard continues east into Rialto, where the SR 66 designation resumes. SR 66 continues east into San Bernardino, before curving to the north as 5th Street and terminating at I-215 south of downtown.
California's legislature has relinquished state control of the segment from the Pomona–Claremont line east to the Fontana–Rialto line, and turned it over to local control.
SR 66 is part of the California Freeway and Expressway System, although it is neither a freeway nor an expressway. SR 66 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.

## History

As a state route, SR 66 was added to the state highway system in the 1964 state highway renumbering, from SR 30 around San Dimas to San Bernardino. By 2013, the portion from east of Pomona to the eastern boundary of Rialto had been relinquished to the various cities that the route passed through.

## 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 numbers reset at county lines; the start and end postmiles in each county are given in the county column.
| County | Location | Postmile | Destinations | Notes |
| Los Angeles LA R0.19-5.34 | La Verne | R0.19 | Foothill Boulevard | Continuation beyond SR 210; former US 66 west |
| Los Angeles LA R0.19-5.34 | La Verne | R0.19 | SR 210 (Foothill Freeway) – Pasadena, San Bernardino | Interchange; west end of SR 66; future I-210; SR 210 exit 47 |
| Los Angeles LA R0.19-5.34 | La Verne | 1.73 | Fruit Street, White Avenue | |
| Los Angeles LA R0.19-5.34 | Pomona | 2.54 | Garey Avenue | |
| Los Angeles LA R0.19-5.34 | Pomona–Claremont line | 3.22 | Towne Avenue to I-10 / SR 210Module:Jct error: Invalid "to" argument | East end of state maintenance |
| Los Angeles LA R0.19-5.34 | Claremont | 4.16 | Indian Hill Boulevard | |
| San Bernardino SBD 0.00-23.05 | Upland | 0.58 | Central Avenue | |
| San Bernardino SBD 0.00-23.05 | Upland | 1.69 | Mountain Avenue | |
| San Bernardino SBD 0.00-23.05 | Upland | 2.78 | SR 83 (Euclid Avenue) to I-10 | |
| San Bernardino SBD 0.00-23.05 | Rancho Cucamonga | 4.08 | Grove Avenue | |
| San Bernardino SBD 0.00-23.05 | Rancho Cucamonga | 6.15 | Archibald Avenue | |
| San Bernardino SBD 0.00-23.05 | Rancho Cucamonga | 7.33 | Haven Avenue | |
| San Bernardino SBD 0.00-23.05 | Rancho Cucamonga | 9.80 | I-15 (Ontario Freeway) | Interchange; I-15 exit 112 |
| San Bernardino SBD 0.00-23.05 | Rancho Cucamonga | 10.33 | Etiwanda Avenue | |
| San Bernardino SBD 0.00-23.05 | Fontana | 12.33 | Cherry Avenue | |
| San Bernardino SBD 0.00-23.05 | Fontana | 14.36 | Citrus Avenue | |
| San Bernardino SBD 0.00-23.05 | Fontana | 15.37 | Sierra Avenue | |
| San Bernardino SBD 0.00-23.05 | Fontana | 16.39 | Alder Avenue | |
| San Bernardino SBD 0.00-23.05 | Fontana– Rialto line | | West end of state maintenance | West end of state maintenance |
| San Bernardino SBD 0.00-23.05 | Rialto | 19.13 | Riverside Avenue | |
| San Bernardino SBD 0.00-23.05 | Rialto–San Bernardino line | 20.14 | Pepper Avenue | |
| San Bernardino SBD 0.00-23.05 | San Bernardino | 22.41 | Mount Vernon Avenue | Former US 66 east |
| San Bernardino SBD 0.00-23.05 | San Bernardino | 23.05 | I-215 (San Bernardino Freeway) – Riverside, Barstow | Interchange; east end of SR 66; former I-15E / US 91 / US 395; I-215 north exit 44A, south exit 44 |
| San Bernardino SBD 0.00-23.05 | San Bernardino | 23.05 | 5th Street - Downtown San Bernardino | Continuation beyond I-215 |
| 1.000 mi = 1.609 km; 1.000 km = 0.621 mi |||||