From the Sacramento area head north on Highway 70 to Marysville and then onto Highway 20. Go northeast on Highway 20 to Marysville Road. Turn north on Marysville Road and follow it to New Bullards Bar Reservoir.
From anywhere north of Oroville, first go to Oroville. Then from Highway 162 follow Lower Wyandotte Road to Foothill Blvd. Then pick up Oroville Bango Hwy which becomes Los Verjeles Road. Turn left onto Loma Rica road and the left onto Marysville Road. Marysville Road will take you to the lake. Better yet, turn on your car's GPS.
Travelers from Reno go north on Highway 395 to Highway 70. Follow 70 west to Highway 49. Follow Highway 49 along its winding route until you come to Marysville Road (just past Comptonville).