Prehistoric cultural affiliation(s) include Achomawi-Astariwawi, Achumawi, Native American, Modoc, Achomawi Astrawawi, Achomawi (Pit River Tribe), Tapaslu, Achomawi-Astarowawi and Hantoo dating back to 6999 BC.
The famous person Capt. Jack is associated with one of more of the Modoc County historic places.
Some of the country's most noteable architects helped create the Modoc County places including WCCA, War Relocation Authority US Army and Martin & Diamond. Prominent architectural styles found in Modoc Country are Gothic Revival, Mission/Spanish Revival and Queen Anne.