South end: SR 37 at Sears Point Major cities Napa | Length 54.02 km | |
 | ||
North end: SR 128 near Lake Berryessa | ||
State Route 121 (SR 121) is a California state highway in the Wine Country that runs northerly from its junction with State Route 37 at Sears Point, past the Tolay Lake basin and across Tolay Creek near Infineon Raceway, veers east at a junction with State Route 116 and Bonneau Road at Schellville, runs eastward through the Carneros region of the southern Sonoma Valley and Napa Valley (concurrent first with State Route 12, then with State Route 29), then northeastward to end near Lake Berryessa in Napa County.
Contents
Map of CA-121, California, USA
The California Legislature named the route Carneros Highway from its southern terminus to its junction with Route 29 in Napa. The stretch between the junctions with Route 116 and Napa Road near the Sonoma/Napa county line is known locally as Fremont Drive. Addresses along the stretch between routes 37 and 116 sometimes use the postal address Arnold Drive, even though that name officially applies only to the county road north of 116.
Route description
This route is part of the California Freeway and Expressway System and is eligible for the State Scenic Highway System. However, it is not a scenic highway as designated by Caltrans.
The route begins at SR 37 in Sears Point. As it continues northward through Sonoma County, it meets SR 116. It then enters Schellville, where it begins a short overlap with SR 12. Upon leaving, it begins another overlap with SR 29, which happens to be a freeway, in Napa County. When it leaves, it continues northward and meets SR 221 in Napa. As it leaves the city, it continues northward for several miles before reaching its north end at SR 128.
History
The section from SR 37 to SR 29 in Napa remains virtually unchanged since its definition in 1963. The northern section, however, was slightly altered since its definition the same year due to a realignment of various other freeways.
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 an overlap due to a correction or change, and T indicates postmiles classified as temporary (for a full list of prefixes, see the list of 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.