Section 421.
Cal. Streets and Highways Code - SHC § 421.
in effectRoute 121 is from:
(a)
Route 37 near Sears Point to Route 29 near Napa.
(b)
Route 29 in Napa to Route 128.
Source: CA Legislative Counsel Bulk DataURL: https://downloads.leginfo.legislature.ca.gov/pubinfo_2025.zipFetched: 6/27/2026