Donald L. “Don” Ryan passed away on January 25, 2026, at the age of 92. He was born in St. Louis Missouri on September 29, 1933. Don graduated from Los Alamos High School in 1951 where he met his future wife Marilyn Bequette. Marilyn also graduated from Los Alamos High School in 1953 where the two became high school sweethearts. Don and Marilyn were married for 69 years.

Don served in the U.S. Navy from 1953 to 1957. After the Navy he attended Oklahoma State University where he received a Bachelor’s degree in Electrical Engineering. Don worked for Los Alamos National Laboratory from 1971 to 1987. He transferred to Lawrence Livermore Laboratories in 1987 and retired in 1993.

Don was an avid fisherman, baseball coach, loved to RV, sail, and ride motorcycles.

He is survived by his wife Marilyn, his daughters Therese, Monica, Elizabeth, and son Christopher. He will be laid to rest in Los Alamos at a later date.