Below is a list of all the locomotives actively tracked on HeritageUnits.com.

Arkansas Oklahoma Railroad

Atchison, Topeka and Santa Fe Railway

BNSF

Canadian National

Chicago Burlington & Quincy Railroad

Coaster

CPKC

CSXT

Duluth Missabe & Iron Range

Georgetown Rail Equipment Company

Indiana & Ohio Railway

Indiana Harbor Belt

James E. Strates Circus

Massachusetts Bay Transportation Authority

Milwaukee Road

Minnesota Commercial Railway

Missouri & Northern Arkansas Railroad

New York, Susquehanna & Western Railway

Nickel Plate

Norfolk & Western

Norfolk Southern

Pere Marquette

Railway Service Contractors Inc

Reading Blue Mountain & Northern Railroad

Southern Pacific

Spokane Portland & Seattle