Oakland Zoo California Trail

Project Details

The California Trail project at the Oakland Zoo doubles the size of the zoo complex to roughly 100 acres and furthers the zoo’s mission of conservation, education and research with a focus on native Californian animals. More than 20 years in the making, the $72 million project was a culmination of community collaboration and the perseverance of the Conservation Society of California. The project includes 26 structures on 22 acres of land and a European-style, aerial gondola system– the first of its kind in California.

Eight native endangered and threatened California species (gray wolf, grizzly bear, black bear, mountain lion, bison, jaguar, California condor, and bald eagle) now live amid rolling hills and oaks, 650 feet above sea level with a view of the SF Bay Area. Visitors reach the hilltop California Trail setting via a four minute gondola ride. The California Trail includes The Landing Café, an overnight campground, a treetop boardwalk, Bay vistas spanning seven counties, and a playground laid out to reflect the ecological zones of California. Inside the California Conservation Habitarium, children use hands-on learning to explore settings replicating mountains, deserts, redwoods, estuaries, and even an urban home.

Overaa’s portion of the work included infrastructure and buildings. The project was completed ahead of schedule and under budget with the help of local labor. To help reach target budget and make the project a reality, Overaa worked with our partners to redesign the HVAC system, provide post-tensioned beams in lieu of conventional concrete deck at the Landing Cafe and propose a Mechanically Stabilized Earth (MSE) retaining wall system. In all, Overaa’s preconstruction efforts saved more than $3M.

During construction, Overaa provided erosion and sediment control measures, and a temporary sound wall was installed to reduce impact of construction activity on the nearby community and wildlife. To preserve the wildlife corridor, a “wildlife exclusion fence” surrounding the construction site was built with cone-shaped outlets designed to help small animals escape the construction zone, while preventing new animals from entering the site.


The Oakland Zoo
Oakland, CA
Best Project Award, Cultural/Worship Category
22 acres on a 56 acre site
  • Colby Powell

    Colby Powell

    Chief Operating Officer

  • Kara Overaa Gragg

    Kara Overaa Gragg

    Vice President, Communications

  • Nick Thompson

    Nick Thompson


  • Ellen Hoffman

    Ellen Hoffman

    Chief Financial Officer

  • I am writing this letter of reference to recommend Overaa Construction. Their work with us at the Oakland Zoo on the California Trail exhibit over a 3 year period was outstanding. Specifically, Overaa provided valuable constructability input as we moved through final design and permitting. We had over 26 unique structures on a very challenging site covering many acres. Overaa helped us reduce cost through material and method changes, while maintaining building quality. They kept to the schedule and turned the project over to us on time for our grand opening. Overaa’s team out of their local Oakland office helped us comply with the many City of Oakland requirements for hiring and the use of local companies. Their familiarity with the permit process in the City of Oakland was a tremendous asset to the project. The Oakland Zoo has worked with many contractors over the years and I can honestly say Overaa was the best of them all. We look forward to working with them again.

    Dr. Joel Parrott

    President and CEO (retired) The Oakland Zoo
  • Once again we say how much we appreciate you – and all you’ve done for California Trail. We know you were the linchpin that held this project together.

    Sarah Becker

    Director of Development, Oakland Zoo