Portland Street Railway Co. - in 1871, opened horse car line on First St., ceased operations in 1896.
Barnes Heights & Cornell Mountain Railway Co. - in 1892, opened electric streetcar line west of Portland serving Mount Calvary Cemetery, ceased operations in 1896.
City & West Portland Park Motor Co. - in 1890, opened steam dummy line south of downtown Portland to Capitol Hill, connecting with Metropolitan Railway Co. on Second St., ceased operations in 1899.
Multnomah Street Railway Co. - in 1882, opened horse car line on Washington St. and Burnside St., with branches south on First St., south on 13th St., and north on 16th St. Electrified in 1890, and extended northwest via 23rd Ave. and Thurman St. In 1892, sold to Portland Consolidated Street Railway Co.
Portland Cable Railway Co. - in 1890, opened cable car line on Fifth St. and Jefferson St. west to Washington Park, with branch south on 18th St. Sold 1892 to City Cable Co., sold 1894 to Portland Traction Co., and electrified in 1896.
Portland City Homestead Railway Co. - in 1890, attempted to open steam dummy cable car line up hill west of Second St. and Gibbs St., never opened and abandoned after 1891.
Portland Traction Co. (original company) - in 1889, opened horse car line on Second St., sold that same year to Metropolitan Railway Co. and electrified. Electric line extended south in 1890 to Capitol Hill. Sold 1892 to Multnomah Street Railway Co.
Transcontinental Street Railway Co. - in 1883, opened horse car line on Third St. and Glisan St., with a branch north via 14th St. and Savier. In 1886, opened additional loop line via Morrison and Yamhill, with branch south on 11th St. In 1891, merged with Willamette Bridge Railway Co. into City & Suburban Railway Co., and electrified in 1892.
Willamette Bridge Railway Co. - in 1888, opened horse car line on Grand Ave., with branch west on Morrison St. across Willamette River Bridge. Also in 1888, opened steam dummy line east of Grand Ave. via Morrison St. and Belmont St. to Mount Tabor Park. And in 1890, opened steam dummy line northeast to St. Johns. Electrification completed of horse car lines in 1990, and in 1991 acquired Transcontinental Street Railway Co. In 1889, opened electric line over newly opened Steel Bridge, and by 1891 opened additional electric streetcar lines northeast of Steel Bridge on Holladay Ave., Interstate Ave., and Williams Ave. In 1890, electric Woodstock line opened southeast of Grand Ave. In 1891, merged with Transcontinental Street Railway Co. into City & Suburban Railway Co. Electrification completed of Mount Tabor line in 1896, and St. Johns line in 1903.
Mount Tabor Street Railway Co. - in 1889, opened steam dummy line on Hawthorne Ave., in 1891 sold to East Side Railway Co., in 1892 extended southeast via Foster Rd., and electrified in 1903. In 1892, East Side Railway Co. opened new electric line south through Sellwood. Sold 1901 to Portland City & Oregon Railway Co., sold 1902 to Oregon Water Power & Railway Co.
Portland & Vancouver Railway Co. - in 1888, opened steam dummy line on Union Ave. north to Columbia River, with ferry connection to Vancouver Washington. In 1892, sold to Portland Consolidated Street Railway Co. and electrified.
Portland Mount Tabor & Eastern Railway Co. - in 1892, opened steam dummy line east of Mount Tabor Park, ceased operations in 1895.
In 1892, Metropolitan Railway Co., Multnomah Street Railway Co., Portland Traction Co., and Portland & Vancouver Railway Co. merged into Portland Consolidated Street Railway Co. But in 1896, Portland Consolidated Street Railway Co. was sold to Portland Railway Co., and in 1900 was sold again to a new Portland Traction Co.
In 1891, Willamette Bridge Railway Co. and Transcontinental Street Railway Co. merged into City & Suburban Railway Co. In 1904, Portland Traction Co. and City & Suburban Railway Co. merged into Portland & Suburban Railway Co., which soon changed its name to Portland Consolidated Railway Co. And in 1905, Portland Consolidated Railway Co. was sold to a new Portland Railway Co.
In 1906, Portland Railway Co. merged with Oregon Water Power & Railway Co. and Portland General Electric Co., forming Portland Railway Light & Power Co., finally unifying the streetcar system, along with the electrical utilities. In 1924, Portland Railway Light & Power Co. was reorganized as Portland Electric Power Co. And in 1930, Portland Electric Power Co. became a subsidiary of Central Public Service Co., with the the street railways becoming known as Portland Traction Co.
In 1932, Central Public Service Co. was reorganized as Central Public Utility Corp. And in 1935, Portland Electric Power Co. regained its independence from Central Public Utility Corp. The last streetcars were replaced with buses in 1950. In 1956, Portland Traction Co. was sold to Rose City Transit Co., which operated buses until the 1969 public takeover by Tri-Met.