Dear Harry, The Great Register is the 1880 Voter Registration for Yuba Co. i don't know that it is on-line. I have a copy of it. I checked for your names. There were the following Hamiltons John F. Age 50. Native of Tennessee. Occupation; Physician. Local residence; East Bear River. Date of registration; Septembe 19, 1880. Dead Hamilton, Josua C. Age 28. Native of Missouri. Occupation, farmer. Local township; East Bear River. Date of Registration; September 19. 1880. Hope this helps. Rosemary