Route 121 is from:
(a) Route 37 near Sears Point to Route 29 near Napa.
(b) Route 29 in Napa to Route 128.
Cal. Sts. & High. Code § 421
The State Highway Routes
Amended by Stats. 1984, Ch. 409, Sec. 47.
Official source: California Legislative Information. Reproduced from public-domain California statutes; confirm against the official source for the current text. Not legal advice.