The Washington Park & Zoo Railway (WP&ZRy) is a 2 ft 6 in (762 mm) narrow gauge[1] recreational railroad in Portland, Oregon's Washington Park with rolling stock built to 5/8 scale.

Opened in three stages in 1958,[2] 1959 and 1960,[3] it previously provided transportation between the Oregon Zoo, Hoyt Arboretum, International Rose Test Garden, and the World Forestry Center.

The extended line through Washington Park, now out of service but still in place, was about 2 miles (3.2 km) long.

[4] The railroad is operational year-round when the Oregon Zoo is open, except in January and part of February, when it is closed for required maintenance.

[5] The short-loop route through the southwest part of the zoo grounds was scheduled to be removed permanently, and during the one-year suspension of service a new section of track was to be laid to create a replacement for the short loop.

In May 2018 an online petition was created in opposition to the Washington Park Master Plan's endorsement to remove the "long route", which runs from the Oregon Zoo to the International Rose Test Garden.

The master plan primarily called for the removal of all tracks so that it could be replaced by a paved twelve foot (12') wide path.

[6] As of May 2020, over 37,000 people have signed the online petition in support of keeping and repairing the, "long route".

Originally named the Portland Zoo Railway, the 1.2-mile (1.9 km)[8] first section of track opened for service on June 7, 1958,[2][9] and was formally dedicated on June 9, more than a year before the zoo opened fully at the same site.

This service used the Zooliner trainset, the railway's first and only train at that time,[2] and operated daily except Mondays through the summer.

[12] It was decided to model the planned steam engine on a real one, a Baldwin 4-4-0 type, and construction began in the autumn, with plans to use it initially at the Oregon Centennial Exposition, scheduled to be held the following summer in North Portland (at the site of what is now the Portland Expo Center).

1 and 2, the Oregon and the Zooliner, served a temporary railway line through the grounds of the Centennial Exposition, which lasted for about three months.

The steam locomotive entered service on June 20,[15][16] and it and the streamlined Zooliner proceeded to carry passengers daily at the exposition all summer.

[15][20] Like the two trains, the small Washington Park "Rose Garden" station building was also first used at the Centennial Exposition and was moved to the new line after the fair closed.

At this time, July 1, 1976, the zoo ownership was transferred from the City of Portland to the Metropolitan Service District, now called Metro.

However, the city of Portland retained ownership of the Zoo railway, and it was leased to Metro at that time.

A suspension of service forecast to last at least through summer 2014 was due to begin on September 23, 2013, to allow construction of a new elephant exhibit area and changes to the railway's route within and near the zoo grounds.

[22] The 1958-built Zooliner and 1959-built Oregon Steamer locomotive, and their respective passenger cars were placed on the National Registry, along with the railroad route itself (including the section within Washington Park), the water tank and tower, the Tunnel-Roundhouse complex and the Washington Park station.

(However, service along this route has been suspended since the fall of 2013 for an undetermined time, as repairs are needed on a few small slides along the track.

[24] In the off-season, weather and business permitting, the 10-12 minute Zoo Loop trip runs.

The Washington Park trips that previously operated during spring and summer months also cover this section.

[25] The Zooliner is a 5/8-scale[26] replica of the diesel-powered Aerotrain, which is famous for its unusual shape that was influenced by automobile designs of the period when it was built, considered futuristic at the time.

The Zooliner was built in 1958, its mechanical parts by Northwest Marine Iron Works[1][18] and its streamlined bodywork by the H. Hirschberger Sheet Metal company of Portland.

It is also normally used during the annual "Zoo Lights" event, held between Thanksgiving and New Year's Day.