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

Alabama & Gulf Coast Railway

Amtrak

Arkansas Oklahoma Railroad

Atchison, Topeka and Santa Fe Railway

Bay Line Railroad

BNSF

Canadian National

Canadian Pacific

Chicago Burlington & Quincy Railroad

Coaster

CPKC

CSXT

Duluth Missabe & Iron Range

EMD

Everywhere West Leasing

Ferry Move

Florida East Coast

GE

Genesee & Wyoming

Georgetown Rail Equipment Company

Great Lakes Central Railroad

Indiana & Ohio Railway

Indiana Harbor Belt

Indiana Railroad

Iowa Interstate Railroad

James E. Strates Circus

Keokuk Junction Railway

Knoxville Locomotive Works

Kyle Railroad

Louisville and Indiana

Maryland Midland

Massachusetts Bay Transportation Authority

Metra

Metro North Commuter Railway

Milwaukee Road

Minnesota Commercial Railway

Missouri & Northern Arkansas Railroad

New England Central Railroad

New Jersey Transit

New York, Susquehanna & Western Railway

Nickel Plate

Norfolk & Western

Norfolk Southern

Pan Am Railways

Pere Marquette

Progress Rail

Providence & Worcester

Railway Service Contractors Inc

Reading Blue Mountain & Northern Railroad

SEPTA

Soo Line

Southern

Southern Pacific

Spokane Portland & Seattle

St. Lawrence & Atlantic

The CIT Group/Capital Finance, Inc

Union Pacific

Webb Asset Management

Webb Rail

Wheeling & Lake Erie

Wisconsin & Southern