Hennessy Development was founded with a simple but powerful vision: to provide property owners and builders across Gallatin County with excavation and earthwork services that meet the highest standards of quality, precision, and reliability.

Owner William Hennessy brings hands-on expertise and a deep passion for the craft of excavation. Every project receives the same level of dedication and attention to detail as if it were our own home.

Working in Montana means understanding the unique challenges of our terrain: rocky soils, variable frost depths, steep grades, and strict environmental requirements. We bring this local knowledge to every job, ensuring your project is built on a solid foundation—literally.

We believe that great earthwork is the foundation of every successful construction project. That's why we communicate clearly, arrive prepared, and deliver results that exceed expectations. Our reputation has been built one project at a time, and we intend to keep it that way.