Tillamook Oldgrowth Forest Park

City of Rockaway Beach- Tillamook Old growth Forest Park

Also known as Big Tree Park, the Tillamook Coast Old Growth Forest Park includes a boardwalk through a wetland area. The project was designed to give local residents and visitors access to a piece of City land that was previously undevelopable and had been conserved due to its unique natural resources.  The site consists of an upland area of old-growth coastal forest and a low-lying wetland area.  The design sought to provide recreational and educational opportunities for visitors to experience this unique ecosystem in two phases by constructing an elevated path over the wetland area and then connecting it to existing paths in the upland forest area, all of which were designed to be ADA compliant.

Tillamook Coast Old Growth Forest Park project Phase 1 included construction of 1,800 linear feet of elevated walkway over the wetlands, a 25’x25’ viewing deck, a footbridge over Saltair Creek, and a 4,500 square foot paved parking area and trailhead.

HBH acquired the necessary federal and state permits, including a US Army Corp of Engineers Nationwide permit and a DEQ 401 Water Quality permit. To avoid disturbing trees, the course of the path was allowed to change during construction so that it could meander around trees. The entire walkway was constructed and completed without heavy equipment.

The boardwalk was six feet wide leaving room for six-inch wide rails and a five-foot wide walking area. The path was ADA compliant. Bumpers (also called Bull Rails) were installed anywhere that the height of the boardwalk was less than 36’’ above the ground surface. The walkway included railings everywhere else.

 The boardwalk was originally designed with the intent of using recycled plastic for the walking surface. Recycled plastic has the advantage of being inexpensive, long-lasting and chemically inert. However, after researching the long term feasibility of Alaskan Yellow Cedar, HBH suggested to the City as a more natural alternative building material for the boardwalk. The City of Rockaway Beach chose to use Alaskan Yellow Cedar. Phase 1 of the project was completed on time and on budget early in 2019. Phase 2 of the project was completed in June 2020.

Due to the sensitive nature of wetlands, no excavation was allowed inside the work area. Diamond Pier footings (pressed into the soil instead of excavated) were used to support the walkway. To avoid placing any kind of disturbance in the creek, the bridge was built to span the entire creek using glulam girder beams for support.

HBH also worked with an archeological consultant for assessing historic artifacts and associated reporting required to meet permit requirements. A Cultural Resources expert was present on site during all ground disturbing activities, including the placement of the diamond piers footings to monitor for signs of objects of cultural significance.