Age 59, passed away May 29, 2013. He was born on October 9, 1953, in Las Cruces, N.M. to James Rae Sims and Fredericka Emile (Utz) Sims. He spent his youth in Las Cruces, Riverside, Calif., and Bozeman, Mont. He spent time rock climbing, spelunking, and participating in a local scout troop. After starting college at Montana State University, he took a two-year break and worked on Kwajalien in the Marshall Islands as a photo optics technician. On his return to the states, he met his sweetheart, Rebecca (Becky) Ewing. He enrolled at New Mexico State University and began pursuing a degree in Mechanical Engineering. On March 13, 1976, he married Becky and they finished their studies at NMSU. In 1976 Jim began work as an engineer for Phillips Petroleum in El Dorado, Ark. and later London, England. They then moved to Los Alamos where Jim worked for 34 years at Los Alamos National Laboratory as a design engineer and leader of project engineering teams. Jim was a gifted Mechanical Engineer with a distinguished career. He was essential to the success of highly-visible programs that have enhanced the scientific and engineering reputation of the Laboratory. He was an internationally recognized expert in high-field magnet design and had an unparalleled knowledge of hardware engineering, design, and fabrication. He was committed to mentoring young engineers, designers, and students, generously sharing his knowledge and experience. His personal character was exemplary and was the foundation for his technical and personal success.Jim and Becky loved traveling together. They hiked around Iceland and trekked the Inca trail to Machu Picchu. They loved the outdoors and skied, hiked, and visited National Parks. Two years ago they totally remodeled their family home, spending many hours together creating a beautiful home that they hoped to retire in.Jim had four children: Jeremy Troy Sims and Christopher Ian Sims who died in infancy, Jessica Diane Sims and Bradford Wayne Sims were born and raised in Los Alamos. Jim was a scout leader in his son's Boy Scout troop for many years. He loved skiing, hiking and traveling with this family. He participated with the local Porsche group and helped to rebuild and repair many local Porsches. He became the local air conditioning and transmission expert. He and his son, Brad, spent many hours working on their own 1973 and 76 Porsches. Jim also made sure his daughter, Jessi, could work on and maintain her car. He spend hours listening to Jessi play her flute and participate with the High School Marching Band and watching Brad play basketball for the Hilltoppers. He deeply loved watching his children grow and become kind, productive adults.He is survived by his wife, Rebecca; and his children: Dr. Jessica Sims (Aaron), Los Angeles, Calif., and Bradford Sims (Clare), Lafayette, Colo.; Father, Dr. James Rae Sims (Toni), Bozeman, Mont.; One brother, George Sims (Pam), of Albuquerque, N.M; Three sisters: Dr. Sioux Stevens (Mike), Billings Mont., Dorothea Dell Sims, Las Cruces, N.M, and Paula Vallejo (Jean Noel), Dayton Beach, Fla.; Grandchildren: Jacob and Emily Rozenek.His funeral will be held at 11:00 AM, June 3, 2013 at White Rock LDS Church, 366 Grand Canyon, White Rock, N.M. There will be visitation from 10:00-10:45, before the service. We will have the burial at Guaje Pines following the service. We will have a remembrance reception back at the church following the burial. It will begin about 2:30. If you have a memory of Jim that you would like to share with the family, bring it with you.In lieu of flowers, donations can be made to the Jim Sims Memorial Engineering Scholarship fund through the Los Alamos Public Schools Foundation.