Design. Innovate. Construct. Succeed.  

Let’s work together

Gray & Osborne has helped cities, special purpose districts, and government agencies deliver successful public works projects to their communities since 1935. Our staff of over 145 experienced design professionals are located in six offices throughout Washington State and represent a broad range of engineering disciplines allowing us to complete most projects without the use of subconsultants, giving us excellent control over schedule, budget, and quality of product.

Our Services


Clean water, once considered limitless, is now a finite resource. Our experts have crafted sustainable solutions for various water challenges across Washington State, including surface water filtration, spring and well development, groundwater contaminants, desalinization, water storage, pumping, and distribution.


As our communities grow and develop, we need to find innovative ways to manage our waste streams to enhancing water quality. Our wastewater professionals prioritize practical technology applications to assist communities in planning, designing, financing, and constructing treatment facilities.


Throughout the Northwest, there is a renewed commitment to reverse the impacts of 125 years of urbanization and changing land uses. Gray & Osborne helps communities use various tools to make real and sustainable progress in surface water quality and salmon recovery.


Transportation facilities are pivotal in a community’s public works infrastructure, fostering commerce and hometown pride. For over 50 years, our professionals have assisted Washington State cities and counties in planning, financing, designing, and implementing transportation improvements.


Underground utilities are the unseen backbone of municipal infrastructure. Increasingly congested right-of-way corridors, new construction methods, and the advent of trenchless technologies have created new challenges and opportunities in the maintenance and development of these vital lifelines.

Featured Projects

Delivering our clients innovation, efficiency, and sustainability.

Our way


At Gray & Osborne, sustainability is integral to our engineering ethos. It ensures environmental responsibility, regulatory compliance, and lasting project viability. Embracing sustainability reflects our commitment to corporate social responsibility, ensuring that our projects are a net positive to our community and are built to last.

Work With Us

We Grow Together

We want every employee and trade partner to feel that they are part of a common good and cohesive team. We help our teams form stronger relationships with trade partners by emphasizing people and teamwork over processes and checklists.

We redefine
what’s possible

Our clients

We’ve worked with approximately 200 diverse clients throughout the state of Washington. View our interactive map of clients here.