California State Route 221
|Defined by Streets and Highways Code § 521|
|Maintained by Caltrans|
|Length:||2.682 mi (4.316 km)|
|South end:||SR 12 / SR 29 near Vallejo|
|North end:||SR 121 in Napa|
Route 221 is the northernmost part of the Napa-Vallejo Highway. It is a divided four-lane expressway that serves as an alternate to the nearby Route 29 freeway into Napa from the south. The southern terminus is with Route 29 (which also carries Route 12), where it continues as the Napa-Vallejo Highway, and the northern terminus is an intersection with Route 121. Route 221 also provides direct access to Napa Valley College and Napa State Hospital.
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 entire route is in Napa County.
|0.00||Soscol Ferry Road||Continuation beyond SR 12 / SR 29|
|0.00||SR 12 / SR 29 – Sonoma, Calistoga, Vallejo, Oakland||South end of SR 221|
|Napa||2.68||SR 121 (Imola Avenue, Soscol Avenue) – Lake Berryessa, Sonoma, Downtown Napa||North end of SR 221|
|1.000 mi = 1.609 km; 1.000 km = 0.621 mi
- California Department of Transportation. "State Truck Route List". Sacramento: California Department of Transportation. Archived from the original (XLS FILE) on June 30, 2015. Retrieved June 30, 2015.
- California Department of Transportation, Log of Bridges on State Highways, July 2007
- California Department of Transportation, All Traffic Volumes on CSHS, 2005 and 2006