On Saturday, Dec. 31, 2022, Leonard C. Truesdell, Jr. of Socorro, New Mexico, passed away after a brief illness. Born in Kansas City, Missouri on Oct. 6, 1937, Len grew up in Winnetka, Illinois and attended New Trier High School.

After graduating from Stanford University with a degree in Chemical Engineering, Len went on to complete his Ph.D. in Chemical Engineering at Case Institute of Technology in Cleveland, Ohio. He worked for many years with Shell Oil Company in California, Louisiana, Texas and New York.

Following his time at Shell, Len began a second career as a professor in Michigan, Colorado and finally in Socorro, New Mexico at the New Mexico Institute of Mining and Technology. Len lived in Socorro for the last 24 years with his wife, Mary Joan Kilgen Truesdell (Joan), where they both loved hiking the mountains and watching the wildlife at their cabin getaway in nearby Mountainair, New Mexico.

Len was a proud member of The Rotary Club of Carbondale (Colorado) and Socorro (New Mexico). Len was a true outdoorsman. In Colorado, he loved hiking, cross-country skiing and mountain biking. In Houston, he participated in the first Houston Marathon with his daughter, Robin, and continued running throughout his life. He and Joan especially enjoyed birding at the Bosque del Apache National Wildlife Refuge and traveling to the North Rim of the Grand Canyon.

Len was predeceased by his mother, Maudine Truesdell, father, Leonard C. Truesdell, and brother, A. Bruce Truesdell. Len is survived by his wife, Joan, his two daughters, Kelly Truesdell and Robin Sher, and their spouses, Christopher Robbins and Jeffrey Sher.

Poppy was loved by his five grandchildren, Chance and Paige Robbins and Olivia, Schuyler, and Annie Sher. Len also enjoyed spending time with his nieces and nephews, Michael, Tom and Claire McGraw, Jonelle Mireles, Daniel and Ryan Camp, and their families.

A celebration of Len’s life will be held at 3 p.m. on Saturday, Jan. 21, 2023, at Epiphany Episcopal Church, 908 Leroy Place, Socorro. A luncheon will follow in the social hall at 4 p.m. Donations may be made in his memory to Friends of the Bosque del Apache, PO Box 340, San Antonio, NM, 87832.

Arrangements are being handled by the caring professionals at the Noblin Funeral Service Belen Chapel, where an online guest register is available at www.noblin.com