Chief Dennen came to County Fire in 1998 after leaving the Running Springs Fire Department as Fire Chief. Once coming to County Fire, he was originally assigned as the Division Chief in charge of the Mountain Division headquartered in Lake Arrowhead. His most challenging assignment came when he was assigned as the North Desert Division Chief covering a vast majority of the Mojave Desert. Chief Dennen served as the Interim Fire Chief for the City of Hesperia during the 2004 transition and contract for fire protection services with the Hesperia Fire Protection District.

In January 2004, Chief Pat Dennen took on the role of Assistant Fire Chief overseeing Fire Suppression Operations and the Training, Safety and EMS Division. By the actions of the County Board of Supervisors in February 2006, Chief Dennen was selected to succeed Chief Peter R. Hills as Fire Chief/Fire Warden responsible for providing fire protection to the largest county in the continental United States.

Chief Dennen entered the fire service in 1974 while still attending high school in Big Bear Lake. Before coming to County Fire, he held positions within the fire service such as Deputy Chief for the U.S. Army’s National Training Center at Fort Irwin, Fire Chief of the Newberry Springs Volunteer Fire Department, and Fire Chief of the Running Springs Fire Department. Chief Dennen has served on the Cal Fire’s Incident Command Team 9 as a trainee and on Team 10 as an Operations Section Chief.  He is C.I.C.C.S. certified as a Type II Incident Commander, Operations Section Chief, and a Division Group Supervisor and Strike Team Leader.  Chief Dennen is also the Alternate Region 6 Fire and Rescue Mutual Aid Coordinator for the State Office of Emergency Services overseeing the movement and deployment of fire apparatus in six Southern California counties in the absence of the Region Coordinator.  Within San Bernardino County, Chief Dennen is the Operational Area mutual aid coordinator for mobilizing and dispatching resources within the county to mutual aid requests throughout the State of California.  Chief Dennen also serves as a Board of Directors member on FIRESCOPE that serves as the governing body of the California Fire and Rescue Mutual Aid system.

With 33 years of experience, Chief Dennen brings with him a very thorough knowledge of the fire service. Chief Dennen holds a Bachelors degree (BS) in Fire Protection, a Master’s Degree (MS) in Fire Department Management, and his second Master's of Science in Executive Fire Service Leadership from Grand Canyon University in Phoenix Arizona.  Chief Dennen also serves as faculty for Grand Canyon University teaching several Bachelors and Masters level courses for the Executive Fire Service Leadership (EFSL) program.

Chief Dennen and his wife Diana hold strong family values. They have made their home in the High Desert in Apple Valley and enjoy camping, boating, hiking, water sports, and most of all, spending time with their children and family.

Updated 8/07