Portland Traction Company Electro-Motive Division (EMD) diesel locomotive number 100 parked in front of engine house at Portland, Oregon, on April 28, 1990. Photo by J.M. Fredrickson. Other Subject Classes: diesel locomotive, switching locomotive.

Portland Traction Company Electro-Motive Division (EMD) diesel locomotive number 100 parked in front of engine house at East Portland, Oregon, on April 28, 1990. Photo by J.M. Fredrickson. Other Subject Classes: diesel locomotive.

Fire fighting train for the miniature railway that operated at the 1959 Oregon Centennial Exposition held at North Portland in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

Portland Zoo "Zooliner" train at the 1959 Oregon Centennial Exposition held at North Portland. in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

Portland Zoo "Zooliner" train at the 1959 Oregon Centennial Exposition held at North Portland. in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

VIP speeder-trolley at the 1959 Oregon Centennial Exposition held at North Portland in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

Portland Zoo Railway 4-4-0 steam locomotive on loan to the 1959 Oregon Centennial Exposition held at North Portland in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

Portland Zoo Railway 4-4-0 steam locomotive on loan to the 1959 Oregon Centennial Exposition held at North Portland in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

Portland Zoo Railway 4-4-0 steam locomotive on loan to the 1959 Oregon Centennial Exposition held at North Portland in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.

Portland Zoo Railway 4-4-0 steam locomotive on loan to the 1959 Oregon Centennial Exposition held at North Portland. Repairs being done on front truck in 1959. Photograph by Alden Raney. Other subject classes: Train-Miniature.