SR 821 is maintained by the Washington State Department of Transportation (WSDOT), which conducts an annual survey on the state's highways to measure traffic volume in terms of average annual daily traffic. The highway's daily vehicle counts range from a minimum of 1,100 vehicles at its northern terminus to a maximum of 5,100 at its southern terminus. SR 821 generally consists of two lanes with a width of , with occasional shoulders, and a posted speed limit of . Sections of the highway are closed for day-long events that are held annually, including a cattle drive in January or February, a marathon and bicycle tour in the spring, and a heritage tractor run in the summer.