At age 24, Brennan stood atop Mt. Rainier at 14,410 feet (4,392 meters), with his dad, Tom- two men bound by a shared achievement that became a lasting bond between them. The following year they continued that journey together on Mt. Whitney.

In May 2017, Tom returned to Mt. Rainier with Kevin, moving slowly over a deep snow base to a quiet place between Glacier Vista and the bend toward Panorama Point. It was there, in stillness above the tree line, that Brennan was remembered. Since then, Tom and Freddi have returned to that same spot – a place marked by sweeping glacier views and the sound of running water. Each visit is different as Mt. Rainier’s weather is unpredictable, offering moments under clear blue skies and others veiled in clouds. Yet through every return the mountain stands majestically, and the meaning of the place remains constant.

It is here that Team O’Brien will mark the 10-year anniversary of Brennan's passing. In August 2026, his friends will attempt a summit of Mt Rainier in his honor while raising money for the T. Brennan O'Brien III Adrenocortical Cancer Research Fund at the University of Michigan Health Rogel Cancer Center. This will be another chapter written in thin air and wide skies.

Team O'Brien 10-Year Climb

Team Members