The Washington Park & Zoo Railway (WP&Z) is a 2 ft 6 in (762 mm) narrow gauge recreational railroad in Portland, Oregon's Washington Park with rolling stock built to 5/8 scale. Opened in three stages in 1958, 1959 and 1960, it provides transportation between the Oregon Zoo, Hoyt Arboretum, International Rose Test Garden, and the World Forestry Center. The extended line is about 2 miles (3.2 km) long. There is also a 1-mile (1.6 km) loop within the zoo grounds.