Gavin Glen Jefferson III

Gavin Glenn Jefferson III was born on March 19, 2005, in Billings, Montana. He passed on to the next chapter of his life on February 1, 2026.

Gavin attended Crow Head Start, Crow School, Lincoln Grade School in North Dakota, Beartooth Elementary, and Medicine Crow, before graduating from Skyview High School in 2023.

Beginning at Beartooth Elementary, Gavin developed a love for running. He competed in cross country and track, including participation in AAU events, earning numerous ribbons and medals throughout his years of competition. He also played basketball during his eighth-grade year.

In high school, Gavin ran cross country and track during his freshman year and continued with cross country throughout all four years. He later discovered a passion for tennis, which he played for the remainder of his high school career. Gavin qualified for Nike Cross Country Regionals all four years and qualified for regionals in tennis for two years.

While in high school, Gavin worked at Walmart for three years and continued his employment there after graduation.

Gavin started working out with his dad, going to the gym 6 days a week. Spending up to 3 hours a day, only having one rest day. Even after moving after graduating, Gavin continued going to the gym on his own religiously.

A year after graduating, he joined the Marines following his big brother's footsteps, who he watched graduate from bootcamp January 19, 2019, and graduating himself from bootcamp October 24, 2025, Echo Company Platoon 2103. He then graduated from Marine Corps Combat Training on November 23, 2025, Fox Co. 3rd Platoon.

Gavin was preceded in death by his grandparents, Michael and Jacqueline Ware, uncle Melvin Pretty Weasel "AKA uncle E"; grandpas Gavin Jefferson, Sr., Carles Jefferson, Albert, and Daniel Takes Enemy; grandmas LeeAnn Old Bull and Dorthea Dust; uncles Pius Takes Horse, and aunties Carolyn Spotted and Easter Takes Horse.

Gavin is survived by his mom and dad Gavin and Lisa Jefferson, Jr., his birth mother Trina Ware-Sanford, step-father Kevin Sanford, half-brothers Damarion and Legend Ware; aunts and uncles Cody (Carlotta), Glen, and Rusty Ware; as well as a host of aunts, uncles, and cousins on the Ware side of the family; siblings Donna, Kaiya, Landon Jefferson, D.J. (Jenice), Darin (Tysha), Devin (Aiyana) Oleyte, Solomon (Angelina), Silas, William, Tre Howe, Sian (John) Bear Below, Julian, Mackayla, Dale Jr., Logan Jefferson, Mikayla (Dominic), Tavian, Tysa Jefferson, Jerelle (Tyra), Treston, Peter, Jr. Big Hair; grandparents Karen, Maxine, Franklin (Verna) Johnny, Steven, Tim (Edwina), Evelyn, Dave (Lilly), Raymand, and Arnold (Coretta) Jefferson, Vanessa, Pauline, Shobe, Orland (Barbara), and T.R. (Stephanie) Little Light, Geraldine Schinderline, Jackie (Larry), and Dwayne (Michell) Blacksmith, Kenneth Spotted, Robert (Frances), Jerry (Ernestine), and George Pretty Weasel, Jonathin (Trudy) Takes Enemy, Judy, Junetta, Frey Jefferson, and Denise Nomee, Leitha (Dan) Gun Shows, Dorthy North Peigan, Melissa Falls Down, Ernestine Jefferson, and Lawrence "Pete" Big Hair; uncles Dale (Serese), Amigo (Lucinda), James (Angel), Jeremy (Jessica), Josiah, Eric, Randall Jefferson, Peter (Andrea) Big Hair, Josh Stewart, Todd (Airiann), Wade, and Dunny (Ranna) Amyotte, Todd (Tressie) Wilson, Bryan (Sierra) Singer, Scott, and Emmette Old Bull, Victor (Verena), and Bernard (Deline) Dust, Jr., Mike, and Tim Dust, Jamie Todd Yellowtail, Shawn Jefferson, and Donald Stewart.; aunts Bernadine (Paul) Nomee, Bernadette (Claude) Dawes III, Sherri (Clinton) House, Barb (Willy) Gardener, Stephanie (Barry) Pretty, Sr., Carlene, Barbara Bernice (Victor) Passes, Londa (Cade) Baker, Sr., Alfeda (Henry) Reed, Sr., Angel Valencia, Annie Jo Old Bull, Veranda (Tylan) Begay, Frey Jefferson, Stephanie Lorenzo-Rico, Charlene Hogan, Felicia (Jerald) Sage, Jr., Tasha Lee (Lex) Pierre, Naomi (Erving) Lewis, Vestal Black Smith, Marilyn (Bryce) Rogers, Marsh (Zach) Wilson, Sr., Karri Ann (José) Medina; his special friends whom he took in as brothers Dillion Freitag, Austin Lee, Brennan Wilson, Steven Burkhardt, Caleb Tonning, Zak Waller, and Michael Kennedy.

The extended family includes Ware, Birdinground, Three Irons, Pretty Weasel, Hunts the Arrow, Fire Bear Yarlott, Doyle, Shane, and Carpenter.

We would like to thank all family and friends for your support during this difficult time, for being here for us as well as for him. Please forgive us if we've forgotten you, as we have a large family.