SR 21 Begins at Jct SR 260 in Kahlotus and heads north to the Canadian Border via Lind, Odessa, Wilbur, the free Keller Ferry across the Columbia River, and Republic. SR 21 continues as BC 41. When first posted in 1964, the southern terminus of SR 21 was at Jct US 395 near Lind. It was extended south to Kahlotus in 1983. SR 21 is now 191.34 miles long.
Before 1964, SR 21 from Lind to Wilbur was SSH 4B; from Wilbur to Republic, part of PSH 4; and from Republic to the Canadian border, SSH 4A.
Primary State Hwys Secondary State Hwys