Lake Washington Boulevard E. runs north and south through the park, parallel to the creek. A secondary road, for most of its length named Arboretum Drive E. and for a short northern stretch named E. Foster Island Road, runs along the Arboretum's eastern edge. E. Interlaken Boulevard and Boyer Avenue E. run northwest out of the park to Montlake and beyond. State Route 520 cuts through Foster Island and the Union Bay wetlands at the park's northern end, interchanging with Lake Washington Boulevard just outside the arboretum entrance. A footpath winds underneath the freeway overpasses and over boardwalks, along the Lake Washington ship canal, and into the gardens of the Arboretum.