Born and raised in Rockford, Iowa, a town of fewer than 900 people, Jon showed little interest in reading until his freshman year of high school, when his mother offered to buy him any book he wanted. He chose Richard Marcinko's Rogue Warrior and became instantly consumed by the story of the Navy SEALs. From that day forward, every school project and book report was about the Teams.

Jon enlisted the summer after his junior year of high school, in 1994, but found the SEAL pipeline full after graduation. Undeterred, he took an intelligence assignment, graduated A-school at the top of his class, and finally entered Basic Underwater Demolition/SEAL training in October 2001, weeks after September 11th. He completed BUD/S Class 238 in April 2002 and earned his Trident.

Jon deployed twice to Iraq, earning a Bronze Star for bravery under fire, and twice more to Afghanistan, before advancing through the Naval Special Warfare Development Group's elite sniper selection course. Those who served with him described a man of contradictions: a ferociously disciplined athlete who ran marathons and triathlons, and a gentle, easygoing presence friends called a "human Labrador," someone you simply wanted with you everywhere. A family friend, worried when he enlisted, said, "I just hope they don't take his sensitivity away from him." Those who trained him were emphatic: they didn't.

Jon's constant companion through it all was his chocolate Labrador, Hawkeye. On August 6, 2011, Petty Officer Tumilson was aboard the CH-47 Chinook helicopter callsign Extortion 17, part of a Naval Special Warfare quick reaction force responding to support U.S. Army Rangers engaged with insurgent forces in Wardak Province. When the helicopter was struck by a rocket-propelled grenade, all 38 aboard were killed, the greatest single-incident loss of life in Naval Special Warfare history.

At his funeral in Rockford, more than 1,500 people, nearly twice the town's population, filled the gymnasium. Hawkeye walked to the front, lay down beside the flag-draped casket, and did not move for the rest of the service. The photograph of that moment traveled around the world, a wordless expression of grief that reminded a nation of the quiet devotion behind every uniform. Special Warfare Operator First Class Jon T. Tumilson gave his life exactly as he lived it: fully, generously, and for the people he loved.