Sentry started as a one-crane outfit serving the oilfields of western North Dakota. One crew. One customer at a time. That’s how we built our name and our reputation. We showed up, worked hard, and found a way to get it done.

Since then, we have grown well beyond the oilfields, expanding into commercial, industrial, and infrastructure construction. What hasn’t changed is our mindset: stay grounded, stay flexible, and always put the customer first.

Today, Sentry operates as a self-performing general contractor and design-build construction firm with offices in Watertown, Sioux Falls, and Pierre. Our growth reflects the trust of our clients and the dedication of our people. We deliver projects across the Midwest through in-house divisions that include Electrical, Mechanical, Structural Steel, Manufacturing, SD Services, Workover, Automated Controls, Architectural, and Crane & Trucking. This depth of expertise allows us to control quality, schedule, and safety, while providing one point of contact from concept to completion.

Whether managing a commercial facility, fabricating a custom component, or executing a plant shutdown, our people bring precision, purpose, and pride to every job. We deliver flexible solutions, innovative thinking, and real results – the kind of follow-through that turns customers into long-term partners.

Sentry: Flexible. Innovative. Results.