About Us

Established in 1999 MSI Engineers provides professional mechanical, electrical and plumbing engineering design services.

MSI is rooted in strong client relationships and a laid-back, professional culture that encourages collaboration and innovation. We’re driven by partnership, focused on delivering thoughtful, client-centered solutions, and proud to be part of a vibrant A/E community that keeps us connected and inspired. Backed by the legacy of our firm’s long-standing history, we bring decades of expertise, consistency, and trust to every project. Our deep roots in the industry inform our forward-thinking approach, allowing us to blend time-tested knowledge with fresh ideas that meet today’s challenges. This foundation strengthens our commitment to quality service and meaningful partnerships across the Northwest and beyond.

Leadership team

At MSI Engineers we’ve embraced the collaborative model of leadership to capitalize on the principal’s and staff’s different but complementary backgrounds and skill sets. From our receptionist to our principals, each member of our staff is encouraged to share their ideas and be open minded. As principals we provide clients with the leadership, expertise, and support needed for successful projects, while also striving to empower our employees with guidance, direction and opportunity.

A middle-aged man with light skin and short, light brown hair is smiling slightly, wearing a blue short-sleeve button-up shirt, standing in front of a plain gray background.

Jess Stauffenberg

PE, LEED AP, Principal, Mechanical Engineer

Experience: 28 years
Education: University of Wyoming
Licensed: WA, ID, OR, WY

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Aaron Donnelly

PE, Principal,
Mechanical Engineer

Experience: 26 years
Education: University of Idaho
Licensed: WA, ID, OR, NY

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Natalie Johnston

PE, LEED AP, Principal, Mechanical Engineer

Experience: 21 years
Education: Gonzaga
Licensed: WA, OR, ID, HI, CA

A man with light skin, short hair, and a receding hairline is wearing a blue polo shirt and smiling slightly. He is posed in front of a plain gray background.

Ben Jennings

PE, Principal,
Electrical Engineer

Experience: 18 years
Education: Washington University
Licensed: WA, OR, ID, MT, WY, CA

A man with short light hair and a beard is wearing a blue collared shirt and standing in front of a plain gray background, looking at the camera with a neutral expression.

Jason Hamm

PE, Associate Principal, Mechanical Engineer

Experience: 21 years
Education: Montana Technological University, 2014
Licensed: MT, UT, CO, WY, TX, WA, CA, ID

Culture and Quality Lead Everything We Do

At MSI Engineers, we take design and company culture seriously—but not ourselves.

Our team is a diverse group of thinkers, creators, and problem-solvers, each bringing unique skills, experiences, and personalities to the table. What unites us is a shared passion for sharp ideas and smart design. We believe that great ideas can come from anyone, and we’ve built a culture where every voice is heard and valued.

Whether we’re leading successful projects or helping each other grow, we’re driven by creativity, leadership, and a commitment to fostering an environment where people can thrive.

That same mindset reaches beyond our office walls. We take pride in contributing to the built environment of the communities we serve—and we’re humbled by the lasting, positive legacy some of our projects will carry into the future. We work hard to ensure that every team member—not just those whose names appear on a plaque—feels ownership of the work and its impact.

With offices in Spokane, WA, and Missoula, MT, we’re proud to be deeply connected to the people and places we serve.

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Locations

Spokane

Our downtown Spokane office is where it all began—our roots, our passion, and our commitment to quality engineering design. From this inspiring and beautifully designed space, we continue to deliver high-quality solutions while fostering strong partnerships and a collaborative culture. It’s more than just an office—it’s where innovation and teamwork come together to shape the future.

108 N. Washington, Suite 505
Spokane, WA 99201
(509) 624-1050

Missoula

Located in the heart of downtown Missoula, our Montana branch allows us to offer MSI’s high standards, expertise and partnership-driven services to clients across the Northwest and Rocky Mountain region. Whether you’re in Spokane or Missoula, you’ll experience the same laid-back, collaborative environment that fosters fresh thinking and exceptional work.

115 W Main St
Missoula, MT 59802
(406) 541-0852

Licensed In

MSI currently holds licenses and performs work in these states and are ready for more on a moments notice.

Washington, Oregon, Idaho, Montana, Wyoming, California, Utah, North Dakota, Texas, Colorado, South Dakota, New York, Hawaii

Map of the US showing MSI is licensed in Washington, Oregon, Idaho, Montana, Wyoming, California, Utah, North Dakota, Texas, Colorado, South Dakota, New York, and Hawaii.