Antone Minthorn is Chairman of the Board of Trustees for the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). He serves as Chair of the Board of Directors of the Confluence Project. A Cayuse Indian, Minthorn first served as Chairman of the Board for CTUIR from December of 1997 to December of 2001. He spent two years as a consultant, then was re-elected as Chairman in December of 2003.

In this role as the top elected official for the CTUIR tribal government, he leads a tribe that is known for its cooperative and innovative approach to issues. Prior to being elected Board Chairman, he spent fifteen years as Chair of the Tribe's General Council – the voting membership.

Before becoming an elected official, he was a staff planner for the Tribe, helping to develop the first Comprehensive Plan, which has effectively guided the Tribe's development and growth for the past 20 years.

Minthorn has played an influential role in many of the Tribe's successes, including restoration of salmon to the Umatilla River after a 70-year absence, development of a modern reservation economy, and re-acquisition of the tribe's land.