High Quality Content by WIKIPEDIA articles! State Route 21 (SR 21) is a 191.34-mile (307.93 km) long state highway in the U.S. state of Washington that traverses four counties: Franklin, Adams, Lincoln and Ferry. The highway extends from an intersection with SR 260 in Kahlotus north through Lind, Odessa, Keller, Republic and Curlew before becoming Highway 41 (BC 41) at the Canadian border in Danville. SR 21 is concurrent with U.S. Route 2 (US 2) in Wilbur and SR 20 in Republic and has two diamond interchanges: at US 395 in Lind and Interstate 90 (I-90) south of Odessa. Between Lincoln and Ferry counties, the roadway crosses Franklin D. Roosevelt Lake on the Keller Ferry, operated fare free by the Washington State Department of Transportation (WSDOT) and the Department of Highways (DoH) since 1930.