Who We Are
VonArx Engineering is a hands-on team that takes pride in doing things the right way: thoughtfully, efficiently, and with a strong sense of ownership.
We believe great engineering isn’t just about technical expertise. It’s about being responsive, staying engaged, and following through on every detail. That’s why our clients work directly with experienced engineers and leadership from the start, and why we stay closely involved through every phase of the project.
We show up, stay focused, and see it through – just like the distance runner depicted in our logo.
Our Story
Since 1977, VonArx Engineering has been guided by a simple philosophy: deliver high-quality work, in a timely manner, for a reasonable fee.
That foundation still holds true today, but how we deliver on it is what sets us apart.
We’ve grown alongside our clients, expanding our services and experience while staying true to what matters most: strong relationships, clear communication, and dependable results.
As a smaller, hands-on firm with big-firm expertise and capabilities, we offer something many larger firms can’t: direct access to leadership, responsiveness, and a team that stays personally invested in your project from start to finish.
How We Work
When you work with VonArx, you’re not navigating layers of communication or waiting for answers.
You’re working directly with experienced engineers and leadership. We’re people who understand your project, your timeline, and your priorities.
That means:
- Faster responses and clearer decisions
- Ongoing communication and project visibility
- A team that takes ownership of your success
We don’t just work for you—we work with you, every step of the way.
Our Approach
Every project is different, and we approach it with that in mind.
We take the time to understand your site, your constraints, and your goals—then develop solutions that are practical, efficient, and built to perform over time. From early planning through final details, we stay focused, adaptable, and engaged to keep your project progressing.
You can expect:
Clear, upfront communication
Accurate, detail-driven engineering
Strong coordination and follow-through
Solutions that balance performance, cost, and long-term value
We take on each project with focus and purpose – seeing it through from beginning to end while creating work that advances your goals and strengthens the communities you serve.
Because getting it right the first time matters.
Interested in having coffee or a conversation?
Our Leadership
Kelley Vonarx
David L. Vonarx, P.E.
Kelley Vonarx
Chief Executive Officer & Co-Owner | VonArx Engineering, Inc.
Kelley Vonarx is the operational and strategic backbone of VonArx Engineering — the force that keeps the firm moving forward, organized, and focused on delivering real results for clients.
As CEO and Co-owner, Kelley is responsible for the firm’s overall direction, day-to-day operations, business development, finance, human resources, and client relations. Since joining VonArx Engineering in 2013, she has shaped the company’s growth with a clear-eyed focus on efficiency, accountability, and long-term value. Her leadership has strengthened the firm’s reputation as a trusted, responsive partner for both public agencies and private developers across Missouri.
Kelley brings over 29 years of professional experience in business operations, strategic planning, and executive leadership. She holds a Bachelor of Science in Business Administration from the University of Missouri – Columbia.
Kelley is deeply committed to empowering women in business and the construction industry. She serves as President of the Festus Chapter of Little Black Book: Women in Business, is an active member of the Professional Women in Building Council of the Home Builders Association of St. Louis and is a member of the Griffiths Leadership Society for Women at the University of Missouri – Columbia. She also serves as a Barn Mentor in the Dream Makers program at GaitWay to Her Success, an equine-facilitated learning program that teaches girls ages 13–18 essential life skills including work ethic, discipline, empathy, grit, responsibility, communication, teamwork, and leadership.
Beyond the office, Kelley is a runner who has completed five half-marathons, and she and Dave co-organized and sponsored the Hillsboro Chamber 5K from 2022–2024. Outside of work, she enjoys cooking, reading, traveling, and tending to her garden. She recently added horse riding lessons and a small flock of baby chicks to the mix keeping life at home as full and grounded as the work she leads. Kelley and Dave have five children, one grandson, and live in Hillsboro, Missouri.
David L. Vonarx, P.E.
President & Co-Owner | VonArx Engineering, Inc.
Dave Vonarx brings over 35 years of civil engineering experience to every project he touches — and a track record of getting complex work done right, on time, and with integrity.
As President and co-owner of VonArx Engineering, Dave leads the firm’s technical work across civil site design, hydraulic engineering, stormwater management, and public works. He has guided projects from conceptual design through construction for residential developers, commercial clients, municipalities, school districts, and public utility districts across Missouri and beyond. He holds a B.S. in Civil Engineering from Missouri S&T (University of Missouri-Rolla) and an M.S. in Civil Engineering from Purdue University and is a licensed Professional Engineer in Missouri and Illinois.
Dave is a firm believer that great engineering is built on relationships. His approach, listening carefully, communicating clearly, and following through, is the reason clients come back project after project.
Dave currently serves on the board of Neighbors Credit Union and The Engineer’s Club of St. Louis. He is a member of the Missouri S&T Athletic Hall of Fame and was inducted into the S&T Academy of Civil Engineers in 2022. He is a Past President of the S&T Academy of Miner Athletics and leads the S&T Mullin/Elmore Leadership in Athletics Speaker Series.
Beyond the office, Dave is a dedicated endurance runner who has completed 31 marathons, including nine Boston Marathons. He and Kelley co-organized and sponsored the Hillsboro Chamber of Commerce 5K from 2022–2024. Dave and Kelley have five children, one grandson, and live in Hillsboro, Missouri.
Ready to Get Started?
Tell us about your project and let’s map out the next steps—quickly and with a clear path forward.