Leadership

Experienced and Enthusiastic

SEMA, where vision meets action and inspiration, sparks innovation. At SEMA, we believe that effective leadership is not merely about directing; It’s about creating a culture of collaboration, empowerment and growth. Here we showcase the individuals who drive our organization forward with their expertise, passion, and unwavering commitment to excellence. Explore the profiles of our dynamic leaders who embody our values and steer us towards success. 

Tom Ames

Founder & CEO

Bradley Spies

President | Southeast District

Brett Ames

President | Rocky Mountain District

Mark Brooks

PE, VP | Rocky Mountain District

Justin Oakes

Vice President | Southeast District

Eric Stepien

Vice President | California District

Jeff Markle

VP | Rocky Mountain District

Geoff Mestas

Vice President | Alternate Delivery

Tom Ames Pro Headshot

Tom Ames

Founder & CEO

SEMA was founded by Tom Ames in Colorado in 1991, though our roots go back to the early 1960s. From 1991 to 1995, SEMA operated mainly as a subcontractor, specializing in mass grading and underground wet utilities, collaborating with heavy highway general contractors in Colorado and New Mexico. In 1995, Tom invited Brad Spies to join the firm as a partner. Brad was a trusted collaborator Tom first encountered in 1984 while working as a subcontractor. Brad Spies brought a wealth of expertise in structural work, a pivotal addition that fueled SEMA’s evolution into a comprehensive general contractor. This transformation equipped SEMA to offer a full spectrum of services, including Earthwork, Utilities, and Concrete Structures—a groundbreaking shift that positioned the company as a pioneer with unmatched efficiency within the construction industry.

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Bradley Spies

President | Southeast District

Brad is SEMA’s Southeast District President and an owner of SEMA Construction, Inc. With more than 40 years of experience in the construction industry, Brad is responsible for the oversight and direction of all personnel and projects throughout the Southeast District in Orlando, Florida. Brad has been instrumental in SEMA’s growth by championing expansion into new markets, including California and Florida. Brad reports directly to SEMA’s Corporate President and Chief Executive Officer.

Brad is the perfect example of how direct owner involvement contributes to SEMA’s strength. It’s been under Brad’s direction that SEMA’s Florida District has grown steadily since its inception—having completed over $700 million in heavy civil work to date. Brad provides hands-on oversight for SEMA’s projects in Florida and is regarded for his sense of urgency when it comes to schedules and deadlines.
Brad has extensive experience in the construction industry, having managed projects in California, Colorado, and Florida. Brad is a structures expert and has a diverse background that includes transportation infrastructure including highways/bridges, reservoirs, commercial buildings, and water/wastewater plants. Over the years, Brad has been directly involved in SEMA’s largest and most complex projects, including the $140 million COSMIX Design- Build Project in Colorado Springs and the $71 million SR 417 & Boggy Creek Interchange Project in Orlando.

Years of Experience:
45 years

Years with SEMA:
30 years

Education:
AA, Applied Science Civil Engineering
Mesa State College

Special Training:
Estimating Course
Metropolitan State College of Denver

Brett Ames Pro headshot

Brett Ames

President | Rocky Mountain District

Brett Ames brings more than 30 years of leadership in the construction industry to his current role as Corporate Vice President and Rocky Mountain President of Colorado-based, SEMA Construction. By spearheading corporate and regional business ventures, Brett is responsible for driving innovation and profitable growth for SEMA. Under Brett’s leadership, SEMA has built a $1.5 billion portfolio in alternate delivery work, completed 80 heavy civil rail projects worth more than $525 million over the past 9 years and has been voted a Top Workplace by the Denver Post for 3 years in a row. Brett is a visionary who is acutely focused on SEMA’s future. He actively pursues ventures that position SEMA as an industry leader while taking a special interest in developing SEMA’s culture. A father of 3 boys, an avid skier and sports fan, Brett brings high intensity and enthusiasm to everything he does.

Education:

• Colorado State University BA in Construction Management

Email:bames@sema.inc

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Mark Brooks

Vice President of Preconstruction | Rocky Mountain District

With nearly 3 decades of tenure with SEMA, Mark has also served as a technical discipline lead for SEMA’s earthwork, underground utilities, water resource and mining divisions. Mark is well versed in all aspects of preconstruction services for both conventional and alternative project delivery methods. Prior to joining SEMA, Mark served as a consulting design engineer with the engineering firm CH2M Hill.

Education:
• M.S. Civil (Geotechnical) Engineering, University of Arizona, Tucson, AZ
• B.S. Geological Engineering, Colorado School of Mines, Golden CO

Community/Industry Involvement:
• Colorado Association of Geotechnical Engineers
• Rocky Mountain Geotechnical Conference Treasurer (1996 – 2020)

Email: mbrooks@sema.inc

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Justin Oakes

Vice President | Southeast District

Justin is a civil engineer with over 14 years of experience in heavy highway construction. As the Vice President of SEMA Construction’s Southeast Division, he has completed projects for FDOT Districts 1,2,5, and 7, the Central Florida Expressway Authority, Florida’s Turnpike Enterprise, Orange, Brevard, and Manatee Counties. Justin was born and raised in Orlando, FL. He holds multiple active professional licenses in Florida including a Professional Engineering license, Certified General Contractor license, Certified Building Contractor license, and Underground Utility & Excavation license.

An avid UF fan, Justin regularly attends Gator games with friends and family. He can also be found boating with his wife, Laura, and their son, Brody.

Education:
• B.S. and M.S. Civil Engineering, University of Florida

Email:
Joakes@sema.inc

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Eric Stepien

Vice President | California District

Eric is responsible for the overall leadership and direction of project success in the Western region which includes projects in California and Arizona. Eric has held several positions within the company including Project Engineer, Project Manager, Project Executive, Lead Estimator and Vice President. Eric’s experience at SEMA ranges from Utilities Projects to Large Transportation Projects in California and Arizona.

Education
• B.S. Construction Management, California State University, Chico

Email: estepien@sema.inc

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Jeff Markle

Vice President | Rocky Mountain District

Jeff is responsible for business development, estimating, and production planning for our heavy bridge and structures work in the DOT, Railroad, and Water Resource projects – both in the Design Bid Build and Alternate Delivery markets. Jeff has held several positions within SEMA, including Lead Estimator, Preconstruction Manager, CMGC Project Manager, and Vice President.

Education:
• B.S. Structural Engineering, Cornell University – Class of 2005
• Culver Military Academy – Class of 2000

Community/Industry Involvement:
• Design-Build Institute of America (DBIA) – National & Rocky Mountain Chapters
• American Railway Engineering and Maintenance-of-Way Association (AREMA) – Committee 15 Steel Structures
• Envision Sustainability Professional (ENV SP)
• Denver Polo Club – Interscholastic Program – Volunteer Coach
• Governor’s Ranch Elementary – Watch D.O.G.S

Email: jmarkle@sema.inc

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Geoff Mestas

Vice President | Alternate Delivery

Geoff leads our Alternative Delivery Group, located in our Centennial headquarters. A Colorado native, he works with each of SEMAs districts to identify and develop our strategic pursuits across the Country. Geoff began his career 2006, serving as a design engineer out of college. His focus as a designer was water resource and roadway design. He has led design teams in every delivery method from design bid build, design-build, CMGC and progressive design build. Geoff worked with SEMA as a design project manager before joining their team in 2021, where he has served in this role ever since.

Education:
• B.S. Civil Engineering, Colorado School of Mines

Community/Industry Involvement:
• Design-Build Institute of America (DBIA) – National Rocky Mountain Chapters
• Envision Sustainability Professional (ENV SP)
• American Society of Highway Engineers

Email:
gmestas@sema.inc