Nevada City can be easily accessed from both the Sacramento International Airport and the Reno International Airport. Once you land, the drive from either is around 1.5 hours. You can rent a car, take the Super Shuttle from Sacramento, or book a car service from Reno.
From Sacramento: Take I-80 east to Auburn. Exit in Auburn at Hwy 49 towards Grass Valley & Nevada City. Follow 49 about 26 miles to Grass Valley & Nevada City. Go through Grass Valley and into Nevada City. Exit Broad Street (directly after Sacramento Street) and turn left over the freeway.
From Reno: Take I-80 west through Truckee. After Donner Summit, exit on Hwy 20 West towards Nevada City. Continue for about 45 minutes into Nevada City. Exit Coyote Street and turn left. Follow down past post office, to 2nd stop sign. Turn right on Broad Street.
From Redding: Follow Hwy 20 from I-5 through Yuba City and Marysville and into Grass Valley. Merge onto Hwy 20/49 towards Nevada City. In Nevada City, exit Broad Street and turn left over the freeway.