A listing and history of the many and varied companies that formed over the years. I’ll try to see if I can set up a database/timeline of the companies and their mergers over the years.
Barnes Heights & Cornell Mountain Railway Company (1890–???)
City & Suburban Railway Company (1891–1904)
City & West Portland Park Motor Company (1889–1901)
City Cable Company (1892–1894)
East Side Railway Company (1891–1901)
First Street Railway Company* (1893–1900)
Kenton Traction Company (1909–1933)
Metropolitan Railroad Company (1896–1900)
Metropolitan Railway Company (1889–1892)
Mount Hood Railway & Power Company (1906–1912)
Mount Tabor Street Railway Company (1889–1892)
Multnomah Street Railway Company (1882–1888)
Oregon Water Power & Railway Company (1901–1906)
Portland & Fairview Railway Company (1890–1899)
Portland & St. Johns Railway Company (1903–1905)
Portland & Troutdale Electric Company (1911–1927)