Jefferson is a town in Grant County, Oklahoma, United States. The population was 12 at the 2010 census, a 67.6 percent decline from th…Jefferson is a town in Grant County, Oklahoma, United States. The population was 12 at the 2010 census, a 67.6 percent decline from the figure of 37 in 2000. Under its former name of Pond Creek, Jefferson was one of the participating towns in the Enid-Pond Creek Railroad War.