Located at 203-1311 Portage Avenue in Winnipeg, District 181 is the heart of the Machinists Union in Manitoba, comprised of four Local Lodges:

LL 608 represents the workers at CNL Whiteshell Labs at Pinawa, as well as the Pinawa townworkers and office staff.

LL 741 represents the workers at Magellan Aerospace in Stony Mountain.

LL 1953 represents the workers at Motor Coach Industries in Winnipeg.

LL 2247 represents the workers at Medivan Inc (stretcher service), Duraco Windows (window and door manufacturing), as well as Keewatin Air mechanics, parts personnel and pilots.

District 181 has an Executive Board and a Delegate Board. The Delegates meet quarterly, or more often if required, to discuss and decide future directions. The Delegate Board represents the members of each Local by an elected representative.

The Directing Business Representative, District Lodge Organizer and Grand Lodge Representatives staff the District Office.

The District Office hosts meetings and provides shop steward, collective bargaining, leadership, and workplace health and safety training for Locals in its jurisdiction.