Approximately a 2.5 hour drive.
When leaving Bass Lake going down the hill you will turn on Ave 12 Madera which will take you to the 99 North. Take 99 North until you hit Merced and then take J59. This will take you through Merced, Snelling and Lake Don Pedro. You will come to a stop sign and that will be the 108. Make a right turn on the 108 and head up the mountain until you hit Rawhide Road in Jamestown. Follow the signs on Rawhide road going into New Melones.
Hope this helps.
Scott