Allnutt Funeral & Cremation - Macy

6521 W. 20th Street, Greeley, CO

A Memorial Scholarship Fund for veterinary students that has been established through the Academy of Veterinary Consultants Foundation (a 501(c)(3) organization) in Dr. Flack's name. Donations may be...

Dr. Duane Elliott Flack

June 7, 1935March 31, 2020

Duane “Doc” Flack was born June 7, 1935, in Albuquerque, New Mexico to Lula Markley Flack and Carroll Elliott Flack. When Duane was young, the Flacks moved to Greeley, Colorado and added a brother, Norman Eugene to the family. Duane passed away March 31, 2020.

Duane graduated from Greeley High School in 1953. In December 1956 Duane married the love of his life, Colleen Barnett of Greeley. On that day, the “new” First Congregational Church opened its doors for their very first services. He continued his education at Colorado A&M graduating in 1957 with a Bachelor’s Degree in chemistry, then received his Doctorate of Veterinary Medicine from CSU in 1959. In 1965 Duane joined Monfort of Colorado as their resident veterinarian. During his 32 years there, Doc grew with the company to become Manager of the Feedlot Division and a Group Vice President of Monfort of Colorado. Toward the end of his career with Monfort, with a desire to help the beef industry increase productivity and add value, Duane created and was the CEO of Monfort Integrated Genetics. Duane also served as President of Colorado Cattle Feeders, Director of the National Cattlemen’s Association, Member of the Food Animal Task Force of the AVMA, the Foreign Diseases Committee of the USDA, and the Advisory Committee to the Commissioner of the Food and Drug Administration. In 1991 Doc was awarded the Colorado Cattle Feeders’ “Top Choice” Consultant of the Year, and in 1996 the Award of Excellence from the American Association of Bovine Practitioners. Duane was an honored Alumni and Faculty member of CSU College of Veterinary Medicine and Biomedical Science. Dr. Flack, among other things, was also recognized as the Man of the Year by the Greeley Jaycees, and National Veterinarian of the year. Without hesitation, Doc would attribute the weight of his achievements to the company he worked for, and the people he worked with.

After retiring from Monfort, Duane formed Associated Agricultural Consultants. Doc continued his work both nationally and internationally training others to farm, raise cattle, manage resources, and how to provide their communities with life sustaining professions and food sources.

Among a number of organizations he belonged and contributed to, one of his favorites was being a member and President of the Milliken Fire Protection District Board of Directors. During his tenure, he was instrumental in the transition from an all volunteer department, to what has now become the volunteer and career firefighters department, Front Range Fire Protection District.

Dr. Flack was a true patriot who loved America. He was a member of the ROTC in college, an avid student of WWII, organized community caucuses, and served as a delegate to Republican State Convention.

Duane and Colleen had three daughters; Cynthia, Lauretta, and Susan. No matter what else demanded his attention, Doc’s family always knew that they were his first priority.

Duane was preceded in death by his parents, in-laws, and daughter Susan. He is survived by his wife Colleen, brother Norman (Linda), his daughters and their husbands -- Cynthia (Kerry Vance), Lauretta (Dr. Mark Smith), Grandchildren and Spouses -- Christine (Chad), Kelly (Jesse), Nicholas, Justin, Levi, Jacob, Lucas (Antoinette), Garrett (Lindsie), Lindsey, and Great-Grandchildren -- Rogan, Henry, Harrison, Taylor, Kadence, Aiden.

Doc was a deep thinker, a masterful planner, had a heart of gold, and was a man of rare character. He will be greatly missed.

A Celebration of Life is scheduled for Thursday, August 6, 2020 at 1:00 p.m. at Allnutt Funeral Service - Macy Chapel, 6521 W. 20th Street, Greeley, CO 80634

Memorial Donations may be made to Meals on Wheels of Greeley and Weld County, or to a Memorial Scholarship Fund for veterinary students that has been established through the Academy of Veterinary Consultants Foundation (a 501(c)(3) organization) in Dr. Flack's name. Donations may be sent directly to the Academy of Veterinary Consultants Foundation, 305 W. Magnolia Street #267, Fort Collins, CO 80521, 970-218-0392, or in care of Allnutt Funeral Service, 6521 W. 20th Street, Greeley, CO 80634.


  • Meals on Wheels of Greeley and Weld County
  • The Academy of Veterinary Consultants Foundation


6 August

Celebration of Life

1:00 pm

Allnutt Funeral Service - Macy Chapel

6521 W. 20th Street
Greeley, Colorado 80634


Dr. Duane Elliott Flack

have a memory or condolence to add?

Thomas West

August 2, 2020

I just saw the notice in the paper for Duane's service. I'm sorry to see that he is gone. I always appreciated Dwayne and Colleen and their hospitality and thoughtfulness to others. Collene, my thoughts are with you as you meet these new challenges in life.

Laura McBride

April 8, 2020

Dear Aunt Colleen, Cynthia and Laurie, my thoughts and prayers are with you all. Growing up with the Flack clan holds so many beautiful memories. Learning to feed the calf in your back yard. Learning to cook corn exactly the way you and Uncle Duane used to, SO DELICIOUS. We absolutely adored our Colorado cousins and feeling a connection to our Greeley roots! Uncle Duane loved his family so very much. His wife and girls were his world. Goodbye for now, sweet man.
Laura Imes McBride

Kent Erickson

April 7, 2020

Sorry to here this - my deepest condolences to you all - -

Rose Stoller

April 7, 2020

My thoughts and prayers are with you Colleen and your family. May God wrap His loving arms around you and give you peace.

Dan & Deb Austin

April 7, 2020

Colleen, Laurie, and families, Deb and I want you to know we are thinking about you during this time of loss. May God hold you and your families close.

Julia Freemyer

April 7, 2020

Thinking of you as you grieve the passing of Duane. Lots of fond memories of the Flack Family when we were at CSU and later as neighbors in Greeley. Prayers and heartfelt sympathy to you Colleen, Cindy, Laurie and all your extended family. May God’s arms enfold you and bring you comfort at this hard time. Love, Julia

Debi Armstrong

April 7, 2020

Colleen we are so sorry for your loss. Our hearts and prayers are with you at this difficult time. love from all your friends at the American Cancer Society

jim Lutey

April 6, 2020

So sorry about your loss, Colleen. You are in our thoughts and prayers.

Susan (Foulk)Breeden

April 6, 2020

Colleen I am so sorry to hear this news. You are definitely in my thoughts.

Betty Jo Gigot

April 3, 2020

So sorry to get the news. Prayers to you all.

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