Daniel Person Johnston passed away on October 19, 2020, in the comfort of his home surrounded by family. Dan is survived by his children, Mishelle Wendel, Saboin Vifquain and Mike Johnston; his grandchildren, Rhys, Joseph, Danny, Caylin, Oakley and Ben; his four brothers and two sisters; Tom Johnston (Juanita), Aurora, CO; Patricia Wellinger (Tom), Chesterfield, MO; Matthew Johnston, Minneapolis,MN; Timothy Johnston (Kristi), Naperville, IL; Greg Johnston(Diane), Edmond, OK; and Jane Crompton (Dave), St. Paul, MN. He was preceded in death by his brother Joseph (1984), brother Mike (2019), his parents, Joan (1985) and Kelly (1987) Johnston; a niece, Michelle Johnston (2012), and the love of his life and wife of 33 years, Mary (2015).

Born June 30, 1951 in Rapid City, SD, Dan attended Cathedral Grade School and Cathedral High School through his junior year due to school closure. He graduated from Rapid City High School in 1969. During his grade and high school years, Dan displayed a strong affinity for chemistry while doing experiments with his Gilbert Chemistry set. He liked to mix items like potassium and water or sodium nitrate and powdered aluminum to create unexpected explosions, which occasionally occurred in the basement, causing many concerns of a potential house fire. He did the majority of his experiments in the family’s backyard over the years. Needless to say, everyone was amazed at his knowledge of chemistry.
In his younger days, Dan would read voraciously about science and about the natural and physical world around him. He collected insects, stamps, and a variety of minerals and rocks over the years. He and his brother Mike would go rock and fossil hunting on a regular basis.

Dan had a strong attraction to animals over the years, including a mud duck, giant turtles from the “Meade Street River”, pigeons and even a screech owl. The most famous was a basset hound with a pedigreed name, Dr. Watson. In its early years, the dog was fed so much that his front legs had trouble holding up his weight, but eventually the dog became much healthier and lived for over 12 years. The family moved to Bismarck, ND, and at that time the city was pushing for a leash law to be voted in by the citizens. Dr. Watson had a penchant for escaping the backyard and the local dog catcher had a difficult time catching him on the street. Dr. Watson was featured in a political ad, with his sad looking face, against the leash law. However the law passed and over a period of the next year, Dr. Watson was able to survive the dog catcher’s efforts to capture him. Once Dr. Watson was captured, he faced a very stern judge for the “crime”. The dog was ordered to be given away to a family 150 miles away and Dan was very distraught about this decision. A family from SD came to pick up Dr. Watson and drove 30 miles before realizing that the dog was so sad about leaving his family. Meanwhile, the Johnston brood had gone to Apple Creek to fish and keep our minds off losing their beloved pet. Upon returning home, they found a note on our front door and the dog in the backyard. The judge reconsidered his verdict and Dr. Watson remained with them for several more years.
Dan graduated from the SD School of Mines in 1973 with a Bachelor’s degree in Chemistry and continued on to complete a Master’s degree in Chemistry at the same school. He was first in the family to achieve this milestone.

Upon graduation, Dan ventured to Vermillion, SD, and worked for over 2 years at the SD State Chemistry Lab as a forensic chemist. He then became a teacher at St. Martin’s Academy in Rapid City, SD, for one year, teaching math and science even without a teaching degree. In 1979, he landed a job as a research chemist for quality control at the SD State Cement Plant in Rapid City, SD, for three and a half years. His background in chemistry eventually led him to the SD Department of Transportation in Pierre, SD, where he became a research engineer for over 27 years. His boss, Bob Crawford, introduced Mary to Dan and they were married in 1982. Mary, who had a daughter, Mishelle, was an auditor for the DOT. They both worked in the same building for all those years. Eventually, Dan adopted Mishelle, and the family grew to 5 as Saboin and Mike came along in 1985 and 1986.

Dan had become a scholar in his own right as he pursued the mystery and history of a place called Stonehenge as early as the mid 1980s. Along the way he, Mary, Saboin and Mikey visited Stonehenge and several other stone circle formations across Great Britain to explore their existence. That obsession inspired Dan to write a book with his brother Mike called "Stonehenge Unhinged; The Wheel of the Sun", which took up to 20 years to complete. Dan himself finished two more books in the last 10 years of his life. They were called "The Temples of Albion" and "The Phaistos Enigma".

Dan invented items that were patented while he worked at the DOT. By himself, he created an organic de-icer composition that many other states eventually used. He collaborated with others to invent an insect trap called “Skeeter Deleter” and a newer de-icer composition with different chemicals than his previous invention. Over the years, Dan became very well respected as an expert on cement composition and corrosive elements in the mixture of cement or concrete. He attended many conferences over the years to impart his knowledge to other states. In doing so, he started his own consulting firm in 2005 while still at the SD DOT and became an expert witness, at times, in concrete litigation cases and helping places like airports to build runways properly. Dan’s daughter Saboin fondly remembers a cup filled with concrete that sat in his office and then in his home that read “Dazzle them with Brilliance or Baffle them with Bullshit", which brings a lighter note to summing up Dan’s many accomplishments and contributions in his career field.

Dan and Mary enjoyed many passions and were always together. While raising their children, most weekends were spent traveling to Huron or Rapid City to visit family. Summers were spent traveling to Minneapolis or other far away destinations to visit a larger circle of family. To this end, their kids were raised in a loving circle of uncles, aunts, cousins and more. When they both eventually retired from the DOT, Dan and Mary purchased a car and set off on a month long road trip to explore the Western US. They snaked their way south to Arizona, West to California, North to Washington and eventually made it home in one piece.

Dan was a very attentive husband to his wife Mary, as her health slowly deteriorated over the last years of her life. They were great partners as they raised their three children and lavished attention and love on them and the six grandchildren. Dan was always very giving to his children and grandkids throughout his life, passing on a love of minerals, academics and maintaining an interest in any subject that catches your eye and fires your passion. He looked forward to seeing any or all of the family, especially after the passing of his wife Mary. He will be truly missed by his family.

A celebration of his life will be held on Saturday, November 7. 2020 at 3pm at Behrens-Wilson Mortuary, 632 St. Francis St. Rapid City, SD. In lieu of flowers, a memorial fund has been set up for Dan's grandchildren at Bankwest under "Dan Johnston Memorial Fund" and will go towards helping further their education, account number 1000192228.