Mining union locals: who represents which mine

This site is not affiliated with any union named on this page. Everything below is compiled from each union's own site or a dated local news report, checked 2026-09-07 -- for membership, dues, current job postings, or a grievance, go to the union's own site, linked in the table.

Why Sudbury has two different unions at two different mines

This trips a lot of people up: Vale and Glencore run separate major operations in the same city, and each is represented by a different union. USW Local 6500 represents Vale's Sudbury workforce -- over 2,600 members across mining, milling, smelting and refining. Unifor Local 598 represents Glencore's Sudbury Integrated Nickel Operations -- roughly 800 members across Fraser Mine, Nickel Rim South, the Strathcona Mill and the Sudbury Smelter. Applying to "a mine in Sudbury" without knowing which operator you mean also means not knowing which union, if either, would represent you.

Timmins: a name that may not match the current owner

USW Local 7580 represented the Timmins Porcupine complex under its previous owner, Newmont. That complex sold to Discovery Silver, now operating as Discovery Mining Ltd., in a sale that closed 16 April 2025 (see /mining-towns/ for the full ownership history). We could not confirm from a primary source whether Local 7580's representation carried over to the new owner -- treat that as an open question and confirm directly before assuming either way.

IUOE Local 793: a dispatch model, not a single-employer local

Local 793 works differently from a single-mine local like the two above. It's a much larger union -- more than 17,000 members across Ontario and Nunavut -- covering heavy equipment and crane operators and related mining/industrial trades, and it runs its own dispatch system for temporary positions rather than representing one fixed employer. Its own postings have included work at Baffinland's Mary River mine site in Nunavut, and it runs training campuses in Oakville and Morrisburg. If you're a heavy equipment operator rather than a production miner, this is often the more relevant union to look at.

Building trades: construction and major maintenance, not production

Mine sites also need electricians, pipefitters, and other building trades for construction projects and major maintenance shutdowns -- work that's typically separate from the production workforce represented by USW or Unifor. In the Sudbury/Timmins region that work runs through the Northeastern Ontario Building and Construction Trades Council, which coordinates the individual building trades unions rather than bargaining as a single unit itself.

How dispatch and hiring actually work, in general terms

For a single-employer local like USW 6500 or Unifor 598, you typically apply to the employer directly and become a union member once hired, since the union represents that employer's existing workforce. For a dispatch-model union like IUOE 793, it works more like a trade hiring hall: you join, and the union dispatches members to temporary positions as they come up, rather than you applying to one fixed employer. The exact process, wait times, and requirements to get on a dispatch list are things only the union itself can tell you accurately -- go to its own site rather than relying on a summary here.

Sources

• USW Local 6500 -- Who We Are — accessed 2026-09-07.
• Unifor Local 598 -- Glencore — accessed 2026-09-07.
• United Steelworkers -- 2025 Officers' Report, bargaining agreements (Local 7580, Timmins, under Newmont) — accessed 2026-09-07.
• TimminsToday -- Discovery Silver is the new owner of Timmins' Porcupine gold complex — accessed 2026-09-07.
• IUOE Local 793 -- official site — accessed 2026-09-07.
• Provincial Building and Construction Trades Council of Ontario -- local councils directory — accessed 2026-09-07.