About Us

NorthWest General Engineering is a full service general engineering contractor based in Santa Rosa, CA and specializing in grading, paving, and underground site work projects.

Founder and President, Kevin Holtzinger, along with co-founder, Lawrence M. Gentry started NorthWest General Engineering after more than 8 years doing site work as Lawrence Gentry Construction Company.  In 2000, they created NorthWest General Engineering, A California Corporation, to act solely as an “A license” contractor.

Since then, NWGE’s experience has encompassed projects large and small, including but not limited to commercial and industrial, subdivisions, custom homes, airports, golf courses, educational institutions, wineries, city, state and county projects.

The employees of Northwest General Engineering

The office crew of Northwest General Engineering

Today, NorthWest General Engineering is a family owned and operated business.  We are committed to the value of individual service and attention to detail on every job we do and we understand the importance of having your job completed on time and within budget.


About Kevin


Holtzinger Bros Vintage Photo

Kevin Holtzinger’s experience in the construction industry dates back 40 years. Growing up he was a part of his family’s construction business, Holtzinger Bros Excavating Grading and Paving Co.  that was started in Marin County in 1958 by his father, Harold Holtzinger, Sr.

Kevin began working summers as a teenager and worked his way up from shop helper, to laborer, to equipment operator.  After graduating high school, he obtained his commercial drivers license and also began hauling equipment to and from job sites.  During the five years after high school, he gained experience managing and working all types of projects from residential housing, schools, commercial buildings, shopping centers, parking lots, driveways, etc.

At the age of 23, he and his brother bought the family business from their dad and worked another 10 years before closing the business in 1990 due to the late 80’s recession.  In 1991, Kevin began working for Lawrence Gentry Construction Company and converted a large portion of the company’s revenue from building projects to site work projects.  During this time, Kevin also studied and obtained his California contractor’s license.  NorthWest General Engineering began shortly thereafter.


Tribute: Lawrence M. Gentry

A longtime construction business owner in Sonoma County, Larry passed away in May of 2010.  NorthWest General Engineering would not be the company we are today without the passion, drive, knowledge and experience of our partner and friend, Larry Gentry. This site is dedicated in his memory.