Dorothy Oliveira passed away in Helena, Montana on July 14, 2025 due to cancer. She was born Dorothy Ann White in Sheridan, Wyoming on November 11, 1947 to Melvin R and Nancy H. White at the Reynolds Home. At the time her father was working for O’Dell and Arney at a ranch near Dayton, Wyoming. The family lived in an apartment on the Main Street of Dayton in a building now known as White Horse Bed and Breakfast. In March of 1948 when Dorothy was four months old the family of three moved to the Half-Way Lane between Ranchester and Dayton to what was the beginning of the White Ranch; their address became Ranchester. Second, third, and fourth generation members of the family continue to live and work on the ranch today. Before Tongue River Schools were consolidated from Dayton and Ranchester Public Schools along with a number of rural schools, Dorothy attended Ranchester Schools in a small building in Ranchester which housed grades 1-12. After school consolidation, she attended Tongue River Schools and graduated with the class of 1966. She attended Black Hills State College in Spearfish, South Dakota for two years and graduated from the University of Wyoming in Laramie in 1970. During her senior year in Laramie, she applied for a job teaching in Hawaii and moved to Hilo, Hawaii in August of 1970. She and George Oliveira were married May 26, 1973 in Hilo and soon moved to Bellingham, Washington. They raised their children there, and Dorothy spent many years volunteering in their children’s school and with other activities and being a 4-H leader. She returned to working in education, and when she and George moved to Gillette, Wyoming, in 2002 she continued working in education. In 2008 they moved to Helena, Montana. In 2009 and 2013 their granddaughters Hayden Lee and Hattie Irene were born in Helena, and it was time with them that Dorothy would tell you was her best gig in life. While in Helena, she was involved with the Daughters of the American Revolution and the US Daughters of 1812 which tied in with her life-long interest in family genealogy.
In addition to her parents, Dorothy was predeceased by her daughter Nancy Leilani Oliveira in 2017. Her brother Claude Hillis White died in 1982. Dorothy is survived by her husband of 52 years George Oliveira, her son Christopher and his wife Madalyn, her granddaughters Hayden and Hattie, all of Helena, Montana. Her sister Alice White lives in Sheridan, Wyoming, and her brother Bill White at Ranchester, Wyoming. She has 6 nieces and nephews, and 9 great nieces and nephews. She is survived by her sisters-in-law Penny Oliveira and Adeline Oliveira, both of Hilo, Hawaii.
The family will hold a private viewing. Dorothy will be buried in a private burial in Helena, Montana next to her daughter Nancy.
Service Schedule
Services are pending at this time or no services will be held. If available, please see obituary for more information.
Service Schedule
Services are pending at this time or no services will be held. If available, please see obituary for more information.
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Karen Huck says
Loved talking genealogy with Dorothy. She was a valuable asset to the genealogy library and the many hours that she volunteered. Such a wonderful person.
Elizabeth Guevin says
I enjoyed speaking with Dorothy and emailing her. She was always so nice to me.
Pat Cris[ says
Dorothy, was such an asset to the Montana Society, DAR. We will miss her greatly. Condolences to her family.
Lee Chandler says
It has been a wonderful time knowing and sharing thoughts and conversations with Dorothy. She will always have a special place in my memories. May you rest in peace Dorothy.
Steve Armstrong says
It was delight for my late wife Linnea and me to have known Dorothy over the years due to her connection and work with Oro Fino Chapter – DAR, of which my late wife was a member. There were several DAR/SAR events that we shared in Helena, where Dorothy’s graciousness and kindness was ever present.
My deepest sympathies to Dorothy’s family, her husband George and extended family.
JoAnn Piazzola says
Dorothy was such a special gal. Will truly miss her. She was such an asset to DAR both on Chapter and State levels. Thoughts and prayers to George and family.
Helen Brown says
Dorothy was a great Lady. We loved genealogy. Dorothy and George was on a DAR cruise with me–we had a lot of fun. Her granddaughters were the light in her life–I was glad to know them. I will miss her. Thoughts and Prayers are with George and the family and also with Oro Fino Chapter, NSDAR.
Melinda - DAR Oro Fino Chapter, Chaplain says
It was such a pleasure to minister to Dorothy and George during these past couple of months. My thoughts and prayers are with George and the family. May you know God’s love, peace, and grace today and always as you grieve the loss.
Barb Marcoux says
So sorry for your loss George and family.
Keeping you all in our prayers.
Barb and Ron Marcoux
Patty Donoho says
Dorothy was loved by so many. She will be sorely missed. We had such great chats about the twins in her family and mine. Prayers to George and family, for peace and comfort.