Millport Slough Bridge is located on U.S. Hwy 101 south of Lincoln City. This project includes the replacement of an existing bridge and widening portions of the approach embankments. The site is located on a slough of Siletz Bay, within the Siletz Bay National Wildlife Refuge. The four-lane bridge will be about 400 ft long and will have four pile-supported spans. Design considerations for the bridge include a work area in the intertidal zone and nearby eelgrass and shellfish beds. GRI provided recommendations for foundation support, ground improvement, and embankment design to comply with regulations associated with these environmental considerations. Additional design considerations include a sediment containment system for portions of the work area within the intertidal zone.