G.A. Johnson Construction, Inc. is located in Harrisburg, South Dakota. With over 100 years combined experience in the construction industry, we know and have acquired a strong working relationship with the area suppliers, contractors, and subcontractors. Our staff has managed a wealth of construction projects ranging from small renovations to large multi-million dollar facilities within the Midwest area.
Corey Johnson (President)
Graduated with a Bachelor of Science degree in Construction Management, helped launch G.A. Johnson Construction with his dad and brother, promoted to president in 2007, active in AGC and HBA of the Sioux Empire, licensed Real Estate Broker in the state of South Dakota. 30 years of experience, starting from in the field to running one of the most respected construction companies in the Midwest.
Hobbies: enjoys spending time with his wife and two children, hunting, archery, fishing, snowmobiling, racquetball and occasionally a round of golf
Michael Johnson (Vice President)
Bachelor of Science degree in Business Economics, specializes in EFIS finishes, stone masonry, building custom executive homes, and high quality commercial building projects. He is a member of the HBA of the Sioux Empire and AGC of SD.
Hobbies: enjoys quality time with his family, hunting, fishing, golfing, trap shooting and snowmobiling
Colette Krisher (Accountant)
Colette has worked her career as an accountant in CPA offices and in construction tasked with the preparation of monthly financial statements, daily job costing, contract administration, and managing the day-to-day duties of accounting.
She enjoys spending time with her husband, researching genealogy, traveling, horseback riding, and attending rodeos.
“Do unto others as you would want them to do unto you.” Matthew 7:12
Brent Williamson (Estimator)
Brent is a seasoned construction management professional specializing in estimating commercial projects. With a degree in Construction Management from MTSU, Brent brings a wealth of knowledge and expertise to every project undertaken. Known for a passion for simplifying complex construction tasks, he excels in making projects more manageable and efficient.
Recently relocating to Sioux Falls, Brent is excited to bring his expertise to the local construction industry. Outside of work, he enjoys exploring the area with his faithful companion, taking his dog out for long walks. An advocate for health and fitness, Brent often incorporates physical activity into his routine and is an enthusiast of road trips, always eager to explore new destinations. With a thirst for knowledge, Brent is continuously seeking opportunities to learn and grow both personally and professionally.
Patsy Boeve-Rietz (Project Manager)
Patsy specializes in residential project management at G.A. Johnson Construction, helping clients build their dream homes! Bringing more than seventeen years of experience in the residential and commercial construction industry, she brings a lot to the table to help projects run smoothly. Some of Patsy’s tasks include bidding new construction housing and remodeling, working with owners on selections and designing, and scheduling subcontractors all while making sure our workers and subs stay on task.
Patsy loves farm animals, riding horses, and going on bike rides. She has 3 beautiful children and 3 different kinds of hound dogs that keep her busy. She even sews pajamas and sweaters for her greyhound! Patsy has lived in Sioux Falls most of her life and never wants to leave the Midwest because of her love for all of the seasons.
“I love piña coladas and getting caught in the rain!”
Michael Hageman (Superintendent)
Has 25+ years of experience in the construction industry. Michael is an experienced superintendent who prides himself on providing detail and quality to all of his projects. He has an excellent record of bringing projects in ahead of schedule and within budget. Has been married for 18 years with 3 beautiful daughters.
Hobbies: camping & hunting
George Bosma (Foreman)
Started as a laborer in 79’ working for a general contractor. Graduated in 87’ from Mitchell Vocational Technical School with a degree in Architectural Building Construction and Drafting. 42+ years experience in the construction industry! George is a TOP Notch Carpenter!
Hobbies: pigeon racing, deer hunting, pheasant hunting, and dog training
Ethan Zimmer (Foreman)
Ethan grew up always being hands on working on farms and small projects here and there. He quickly fell in love with the building trade and started pursuing construction. He started his construction career at G.A. Johnson in the spring of 2021 while at Harrisburg High School through the career tech education program and continued on to college where he graduated from Southeast Technical College with an associates degree in construction management in 2023. Ethan has a strong drive to do his best in quality and performance. He is a great asset to the team!
Ethan enjoys building and crafting things, hanging out with friends, and spending time outdoors when not at work.
Jerry Johnson
26+ years managing a top 500 Architectural, Engineering and Construction firm where he was President and CEO of the construction division before retiring and starting G.A. Johnson Construction in 2002 with his sons. He’s been actively involved in AGC of SD. Jerry works as a consultant for the company providing over 40 years of commercial expertise from detention facilities, higher learning facilities, medical, retail, and professional office buildings.
Hobbies: golfing, hunting, fishing, playing guitar, flying model airplanes, spending time with family
“Careful now, you’re talking common sense.”
