Duwayne was born June 30, 1939, in Leedey, OK to James Nolan and Mary Evelyn (Twyman) Graybill and went to be with the Lord on Wednesday, July 9, 2025, at Oxford Springs Assisted Living in Weatherford.  Duwayne was raised and attended school in Leedey and graduated high school in 1957.  His family farmed and ranched in Leedey.  His father was County Road Commissioner for Dewey County.  On December 27, 1959, he married the love of his life, Helen Jean Albright in Palo Alto, CA, and stayed married for 60 years.  They eventually made their home in Santa Clara, CA.  He worked in sales and traveled to various places in California.  During their time in California, Duwayne and Helen brought three sons into the world, Dave, Don and Jim.

In 1977, they settled their family in Weatherford where Duwayne was an instructor at Southwestern Oklahoma State University, teaching industrial engineering and technology. He was heavily involved in SME, Society of Manufacturing Engineers.  Duwayne helped create projects the SWOSU engineering department still uses today.  He left an impression on many students and they admire him to this day.

Duwayne enjoyed spending time with family and friends and going to church at Emmanuel Baptist where he served as a Deacon.  He loved playing dominos and taught all of his grandchildren how to play.  Duwayne got a kick out of being ornery and making everyone laugh.  He also enjoyed golfing and walking his beloved dog, Rosie.  Duwayne is remembered for being an amazing dad, grandpa, great-grandpa and instructor.

Duwayne is survived by his three sons, David Graybill and wife, Stacey, Don Graybill and wife, Lisa, and Jim Graybill and wife, Cindi; three brothers, Virgil Graybill and wife, Wallie, Robert Graybill and wife, Judy, and Calvin Graybill and wife, Verna; sister-in-law, Marie Elaine Graybill; seven grandchildren; eight great-grandchildren; and numerous extended family. He was preceded in death by his parents; wife, Helen; sister, Darlene and Don Leck; brother, Jerry Graybill; grandson, Tyler Graybill; and his faithful dog, Rosie.