Esterly Hall, a.k.a. Crown Point Hall of the Nevada County Board of Realtors is at

336 Crown Point Circle, Grass Valley, Calif. 95945

Here's a printable map.
The road marked "Lower Banner Rd." on the map is actually Idaho-Maryland Road.

From Highway 49 just north of downtown Grass Valley, take the Idaho-Maryland Road exit, travel east for approx. 1/2 mile, then turn right onto Centennial Drive, which makes an immediate left to become Whispering Pines Lane. Continue up the hill on Whispering Pines Lane then turn right onto Crown Point Circle near the top of the ridge (if you overshoot, you reach Brunswick Road.) The Board of Realtors building is at the first left after taking the right fork of the circular road. Crown Point Hall is downstairs, with the door facing west. Additional parking is available on the street and up the hill.

Please carpool if possible.