Mackenzie draws strength from the diverse talents and specialties of our staff. Click on the photos to get to know the members of our integrated team. Looking for a particular person, capability, or job function? Use the filter options or search field below.

Infrastructure

With today's limited funding to repair and replace our infrastructure backbone, the Mackenzie team continues to design our community's roads, parks, and utilities with a focus on the future and added value. Matt Butts leads Mackenzie's work in this market sector.

Brent Ahrend
  • PE
Transportation Planning
Associate Principal, Assistant Department Head - Transportation Planning

Brent Ahrend combines technical skills in transportation analysis and modeling with strong communication and demonstrated abilities to provide...Learn More

Matt Butts
  • PE
  • LEED AP
Civil Engineering
Principal, Director of Civil Engineering & Transportation Planning

Matt Butts leads Mackenzie's Civil Engineering and Transportation Planning departments. Matt manages most of the firm’s infrastructure and...Learn More

Gabriela Frask
Land Use Planning
Senior Associate, Department Head - Land Use Planning

Gabriela joined Mackenzie with experience working as a policy coordinator, as well as in corridor transportation planning. Clients benefit from...Learn More

Bob Frentress
  • PE
  • LEED AP
Civil Engineering
Senior Associate, Civil Engineer

Bob Frentress joined Mackenzie in 1993 after earning a B.S. in civil engineering from Portland State University. He provides street design, storm...Learn More

Ralph Henderson
  • PE
  • LEED AP
Civil Engineering
Senior Associate, Civil Engineer

Ralph Henderson is noted for his technical mastery. He has worked on a variety of projects from roadway improvements to athletic fields and parks...Learn More

Brian Hollenbach
  • PE
Civil Engineering
Senior Associate, Civil Engineer

Brian Hollenbach brings a background of 16 years of experience on commercial, residential, and general civil engineering projects, including...Learn More

Brent Nielsen
  • PE
Civil Engineering
Senior Associate, Assistant Department Head - Civil Engineering

Brent Nielsen earned his B.S. and M.S., with an emphasis on geotechnical engineering, from Montana State University. Brent joined Mackenzie in...Learn More

Steven Tuttle
  • PLA
  • LEED AP
Landscape Architecture
Senior Associate, Department Head - Landscape Architect

Steven Tuttle has more than a decade of professional landscape architecture experience throughout the Pacific Northwest. Steven has been involved...Learn More

Brian Varricchione
  • PE
Land Use Planning
Senior Associate, Land Use Planning

Brian Varricchione, a land use planner and licensed civil engineer, brings 15 years of professional experience. Brian provides permitting and...Learn More