Mark Richard Sinclair

Mark was born in Trenton, New Jersey and grew up in Long Island, NY. In his early years he loved baseball, played in little league, and he was a big fan of the Yankees, collecting baseball trading cards. His favorite Mickey Mantle card was a treasure, but when the family decided to move to California, Mark left those cards behind as he was sad that he could no longer be a Yankees fan. Mark next lived in Sacramento, California, which he thought was very hot and dry— not such an exciting place for him.

By then Mark’s family had grown to three brothers and one sister, Jeff, John, Nancy, and Skip. His parents Warren and Marjorie created a busy home with wonderful game nights–Hearts being the family favorite that carried on for generations. His father worked in aerospace and a new job opportunity brought the family to Littleton, Colorado. After graduating from Arapahoe High School he set his sights on The School of Mines in Golden, Colorado, and where he started as a math major. He soon discovered Chemistry was more exciting, especially when mixing things and playing with fire. Exploring old mines in mountains around Golden created plenty of adventure too. During these years, Mark enjoyed many different sports like handball, baseball, tennis league and also a bowling league. He worked at the bowling alley down the street from campus, and perfected his bowling hook.

Upon graduation from Mines he took a job working for the Federal government and co-authored a book with the department chair during this year at the Fed Center.

Feeling the need to look for a better paying job, Mark moved back to the Golden valley in a lab at Coors Container Company. The lab was growing and he really enjoyed his position there, leading workplace safety and environmental protection for Coors. Mark continued to move up in his career with Coors and subsidiaries of Coors until he retired in 2010. Mark traveled a lot for work and always came home with a unique story, whether about the strange and exotic meals at a restaurant in Tennessee or the printing presses and recycling centers in Germany. Not only did Mark find great fulfillment in work and leadership in his career, the friendships he forged during his time at Coors lasted his entire life. The camaraderie he felt and the talented people he met while working at Coors, and later at Graphic Packaging were friends that lasted to his final days. Mark was proud of his work, the teams he led, and the work he accomplished. Mark was known to many as a kind and bold leader who strengthened the company as well as those around him, mentoring them in their path to leadership as well.

After graduating from college and starting his career, Mark came upon the good fortune of running into Marsha Hill who gave him the name of Sandy Hill, her sister. After some discussion and a handwritten contract, Sandy hesitantly agreed to a blind date with Mark. However, during that first date, Sandy and Mark set up a second date, and the rest is history.

Mark and Sandy were married on June 3, 1972 at Arvada Covenant Church. The honeymoon was the beginning of many travel stories that would be remembered for many years ahead. A book entitled “What Not to Do on Vacation” would be the best way to describe the Sinclair vacations…lots of great stories, cautionary tales, and laughs (after returning from the trip).

On November 21, 1974 Annessa Louise was born–the apple of her daddy’s eye. Being new parents was fun and challenging but Mark learned the ropes easily and happily. In 1977 a son joined the family. Matthew Richard was born on Christmas Day - a little early but another fun adventure in parenting. One more baby was added on December 1, 1981 when Jacob Andrew joined the roster. With the family complete, the fun growing years began. Camping, sports, household improvements, travel, memorable holiday traditions, homework help, and hanging out with neighbors and friends were always on the calendar during those years. Building memories, facing new adventures, and working through the occasional mishap all built what the Sinclairs knew about life together.

Mark was a wonderful dad, always finding time to play, learn, and experience life. There was always a math problem to solve, especially calculating a good tip at the restaurant or building a fort in the backyard, he helped drive a passion for learning, curiosity, and the reward of hard work. The kids knew he was always up for adventure–even to the point of driving through many nights on road trips, even though we were “just 20 minutes away” from the next hotel with a pool. He always had the best level-headed advice, especially during the kids’ teen years, and always shared the importance of caring about who people are and being truthful as important paths to solving problems. He was our very own “MacGyver” –duct tape, and beyond. While always willing to give advice, he often supported his kids by leading them to find the answers within themselves, helping build confidence for their futures. He was a big believer in a strong education and helped drive his kids to the goal of attending college.

As the kids grew up, Mark and Sandy welcomed three new members to the Sinclair clan: Chuck (Annessa), Lindsey (Matthew), and Emily (Jacob), as well as six amazing grandchildren: Dylan and Andrew, Elouise and Catherine, and Liam and Oliver. Spending time together as a family of 14 has been a treasure and gift. Any time spent together with family was good time; Mark was very proud of each and every child and loved them dearly.

Mark loved travel and always kept the calendar filled with some adventures. During retirement, Mark and Sandy continued to travel to all fifty states and many countries around the world creating more favorite and unusual stories. Travel with neighbors, friends, and family always made these excursions that much more enjoyable. These trips led to great storytelling moments, and everyone always wanted to hear Mark tell the story of the funny and unexpected trials of the vacations. Mark also enjoyed photography and loved capturing these memories on film. Many of his beautiful photos have been gifted throughout the years–his eye for a beautiful rainbow, sunset, beach view, mountain, or countryside impressed many.

In 2016, Mark started to experience more difficulties with health, and by 2018, was accepted at the Mayo Clinic in Jacksonville, Florida for a liver transplant due to a genetic abnormality also experienced by two of his brothers. With a great deal of support from the family including his brother, Dr. John Sinclair, the transplant became a reality on September 18, 2018. We were beyond grateful for this new chance at life and so thankful for the immeasurable gift of organ donation. After a year in Florida, Mark was able to return to Colorado. He continued to need frequent medical care and procedures at UCHealth Anschutz where the team came to love Mark’s sense of humor, wit and wisdom and the family knew he was in good hands. While it was never easy, and he had to overcome so much again and again, including a true phobia of needles, he kept a positive attitude that prevailed for many years. All during that time, Sandy stood beside him as support, caregiver, partner, and his strongest love of his life. As complications became more and more difficult, Mark and his family decided to move forward with hospice care. Per his wishes, he was able to stay at home with great support from Sandy, their children, extended family, and great friends. Even when he had very hard days, he kept his spirits up–the visits, the calls, the meals, and the love from everyone all meant so much to him during these difficult days. During his final days, Optimal Hospice Care provided some of the most wonderful professionals for support. Mark passed away peacefully in his home on September 16, 2026. Mark is preceded in death by his parents–Marjorie and Warren, and his brothers Jeffrey and “Skip” Warren, Jr.

Mark is survived by his loving and devoted wife, his adoring children, and his loving grandchildren. The life lessons of generosity, kindness, honesty, love, and adventure that Mark imparted on all of us will live well into years to come.

We will celebrate the life of Mark R. Sinclair on Saturday, October 17, 2026, at 10:00 am at the Table Mountain Events Center at 16035 Table Mountain Pkwy Golden, CO 80403. In lieu of flowers, the family requests those who wish to express sympathy consider making a donation to a local food bank in his name. Mark always found joy and significance in donating to the food bank at church in order to ensure that those in need could find more comfort and security, especially around the holidays.