Mr. Josh F.W. Cook has been appointed as the new United States Environmental Protection Agency (US EPA) Regional Administrator for the Pacific Southwest (Region 9). He will lead the implementation of federal environmental policies for the states of Arizona, California, Hawaii, Nevada, the Pacific Islands, and 148 Tribal Nations. Mr. Cook replaces Ms. Martha Guzman, who left the position in January 2025 and was appointed in 2021 under the Biden Administration.

 “Josh Cook is the right person we need to lead Region 9. He understands the unique nature of the Pacific Southwest and will be a great addition to the EPA team,” said US EPA Administrator Lee Zeldin. “Josh’s talent working with state and local partners will be paramount to power the great American comeback across our regions.”

Mr. Cook’s environmental service includes roles on advisory councils for the U.S. Department of Agriculture and the Department of Interior, as well as serving as a City Planning Commissioner. Before joining the US EPA, he served as Chief of Staff to former California State Senator Brian Dahle (R-Bieber) and to the Minority Caucus in the California Legislature. He also advised the Tribal Council of the Mooretown Rancheria of Concow Maidu Indians.

“I am humbled and honored to take on such a meaningful assignment from President Trump and Administrator Zeldin. While focusing on the core competencies of clean water, land, and air, EPA Region 9 will lead the way in reducing energy costs, creating wealth, and cementing America’s position as a leader in agriculture, energy, manufacturing, AI technology, and transportation,” said Regional Administrator Cook.

Mr. Cook is also a Veteran of the California State Guard and an Associate Professor and lecturer at the University of Southern California. He earned an Associate’s Degree in Languages from Butte College, a Bachelor’s of Science from Charter Oak State College and a Master’s of Science from Cal State University East Bay. Josh and his wife Robin have been married 32 years and are the parents of five children. They reside in Chico, CA, where they actively engage in their church and community.

Read here for more details. Mr. Cook began his tenure as Regional Administrator on Monday, March 17, 2025.