Hubbard Merrell Engineering Team

Hubbard Merrell Engineering

Our Story

Hubbard Merrell was started by Bob Hubbard and Dave Merrell in 2012. Bob and Dave started working together at TOR Engineering in Phoenix, AZ in 1999. After 13 years of success in developing and managing the structural engineering department at TOR, they decided to partner together to further develop the structural department and create Hubbard Merrell Engineering (HM) in Flagstaff, AZ. TOR and HM continue to enjoy a strong working relationship today, while focusing on different engineering disciplines.

HM provides structural engineering services to a wide range of clients, including architects, civil engineers, contractors, utility companies, medical facilities, private home owners, commercial developers and aerial adventure course manufacturers. HM’s staff includes registered professional engineers, certified Engineers in Training, drafters, aerial adventure course experts, engineering student interns and administrative staff. Together, HM has over 80 years of industry experience.

Working and living in Northern Arizona allows us to provide our Arizona and Southwest clients with unmatched knowledge of local conditions and Building Code requirements that affect the structural designs in our region. Our staff provides quick response to our clients’ requests, including on-site consultation during all phases of design and construction.

In addition to our local roots, Hubbard Merrell principals are registered as professional engineers in 28 states and counting. In 2010, Hubbard Merrell (then a part of TOR) ventured into the Aerial Adventure Course structural design world which includes zip lines, climbing walls and challenge courses. Since that time, HM and its staff have become leaders in the aerial adventure course industry, providing cost effective structural engineering for Aerial Adventure Courses including Zip Lines and have become a widely used resource for the most current government regulation information available in the United States. We are continuing to expand our services nationally and internationally as they relate to this industry.

Our Principals

Robert A. Hubbard
P.E., S.E.

Principal / Owner

+1 (928) 526-6174 Ext. 11
David S. Merrell
P.E., M.L.S.E.

Principal / Owner

+1 (928) 526-6174 Ext. 15

Our Team

Geoffrey D. Wertz
M.S.E., E.I.T.

Structural Designer

+1 (928) 526-6174 Ext. 14


Sabrina M. Ballard E.I.T.

Structural Designer

+1 (928) 526-6174 Ext. 21
Brian P. Shepherd


+1 (928) 526-6174 Ext. 16


Jamie L. Miele

Business Manager

+1 (928) 526-6174 Ext. 12
Bob Hubbard

Robert A. Hubbard | P.E., S.E.


Bob was born and raised in Glenwood Springs, Colorado and attended the University of Colorado in Boulder. He graduated with a Bachelor of Science degree in Architectural Engineering, specializing in structural engineering, in 1981.

After graduation, Bob moved to Wyoming and started his structural engineering career. He moved to Phoenix, Arizona in 1984 and continued his profession there until he and his family moved to Flagstaff in 1999.

Bob and his wife Suzanna have two grown children and are now “empty nesters”. They thoroughly enjoy living and working in Flagstaff with all that Northern Arizona has to offer.

+1 (928) 526-6174 Ext. 11 |
Dave Merell

David S. Merrell | P.E., M.L.S.E

Principal / Owner

Dave is a Principal/Owner with Hubbard Merrell Engineering. Dave oversees all engineering production for Hubbard Merrell; including projects, design, review, and coordination with Hubbard Merrell project managers, project engineers, designers, and CAD personnel. He also has direct interaction with project clients, contractors, and other design consultants.

Dave is responsible for structural engineering design and management from start of design to end of construction. Individual engineering services and responsibilities include; preliminary structural systems design, project design, project review, and coordination of structural engineering services provided by Hubbard Merrell Engineering.

Dave’s experience in the Aerial Adventure Course industry goes back to when he worked as a guide at a summer camp as a teenager. He has been designing courses professionally since 2010. Dave has worked on approximately 60 projects across the industry, including; zip line tours, aerial adventure parks, challenge courses, and climbing structures. Dave’s understanding of the available Standards and typical operation of the elements has led to the overall success on these projects.

+1 (928) 526-6174 Ext. 15 |
Geoff Wertz

Geoffrey D. Wertz | P.E., M.S.E.

Project Engineer

Geoff was born and raised in Flagstaff. He graduated from Lewis & Clark College with a Bachelor of Arts in Physics in 2013 and from Arizona State University with a Master of Science in Engineering in 2015. He joined Hubbard Merrell Engineering as an off-site intern during his last semester at ASU in 2015 and became a full time Engineer in Training, moving back to Flagstaff in January of 2016.

+1 (928) 526-6174 Ext. 14 |
Brian Shepard

Brian P. Shepherd


Brian is an Arizona Native, and was born and raised on the Navajo reservation. He has lived in Flagstaff for 16 years, and has an Associate’s Degree in Architectural Drafting. Brian is responsible for all the drafting at Hubbard Merrell and has been working with Bob and Dave since 2007.

+1 (928) 526-6174 Ext. 16 |
Jamie Miele

Jamie L. Miele

Business Manager

Jamie is an Air Force brat who moved to Flagstaff in 1997 to attend Northern Arizona University. She graduated from NAU in 2001 with a degree in Speech Communication and has worked in the civil engineering field providing business management services for 15 years. Jamie is glad to call Flagstaff and Hubbard Merrell her home.

+1 (928) 526-6174 Ext. 12 |
Sabrina Ballard

Sabrina M. Ballard, E.I.T.

Structural Designer

Sabrina was born in Oregon City, Oregon and grew up in Goodyear, Arizona before heading up to Flagstaff to attend Northern Arizona University. She became an intern at Hubbard Merrell in February 2016. She won a first place award for her undergraduate research at the AzASCE conference student competition in September 2016. Sabrina graduated in May 2017 from Northern Arizona University with her Bachelor of Science in Civil Engineering. Not only did she succeed in completing her degree, but she excelled in her program earning the award for Outstanding Student in the College of Engineering, Forestry and Natural Sciences. Sabrina joined the Hubbard Merrell team as a full-time structural designer in May 2017.

+1 (928) 526-6174 Ext.21 |