"For the First Nations of North America, foot trails long provided the main source of transportation behind rivers and the ocean, with individual trails stretching far beyond each tribe's ancestral homeland. In the upper Illinois River Valley and greater Siskiyou Mountains, trails supported complex groups of 'hunter-gatherer-fishers' long before the arrival of gold seeking 'whites'. Modern tribes operating today include the Karuk Tribe, individual member tribes of the Confederated Tribes of Siletz Indians and Confederated Tribes of Grand Ronde, Tolowa Dee-ni' Nation, Yurok Tribe, The Klamath Tribes and others. This thesis serves to identify and interpret ancestral travel routes in the Siskiyou Mountains, with a focus on the Illinois River Valley, situated along the border of southwestern Oregon and northwestern California. By combining archaeological evidence with archival based research, the study seeks to better understand the relationship of trails to the (pre)history of modern tribes, and the contribution ancestral trails played in the rapid development of southern Oregon and northern California. Indian trails described in the written records of fur trappers and explorers were utilized in the colonization and settlement of North America. Indian trails served as the primary routes fur trappers... used to explore the region. This thesis presents evidence of early settlers and gold miners using Indian trails to develop their first settlements and mining camps, improving them for use by pack animals and wagon trains to supply a growing population of immigrants flooding into Indian Territory."--adapted from leaf 3.