The UMWA first endorsed a presidential candidate in 1936, with Franklin D. Roosevelt. Then it endorsed no one else until John F. Kennedy in 1960.
It hasn't sat out a presidential race since 1972, when its choices were Richard Nixon and George McGovern.
The union has, however, picked candidates in some other federal races this year. All are Democrats, with the exception of GOP candidates in congressional races in Alabama and Pennsylvania.
In West Virginia, it's backing incumbent U.S. Sen. Joe Manchin and Rep. Nick Rahall. It didn't choose a candidate in two other House races. In Ohio, Sherrod Brown gets the union's nod for Senate, along with eight House candidates.
In Virginia, the union is behind Senate candidate Tim Kaine, and House challengers John Douglas and Anthony Flaccavento.
Flaccavento is challenging Rep. H. Morgan Griffith, a first-term Republican in southwestern Virginia's "Fightin' Ninth" Congressional District — the state's only coal-rich area.
Two years ago, Griffith unseated Democrat Rick Boucher, who had represented the district for 28 years, because of the perception that Boucher had acted against the interests of the coal industry. Griffith has been an outspoken supporter of coal but has opposed unions.
John Douglass is hoping to unseat first-term Republican Rep. Robert Hurt.
The West Virginia Coal Association has endorsed Romney's presidential campaign and is urging people to register to vote, saying there's never been an election "more vital to the future of our industry, our state and our nation."
"The major challenges and issues facing the industry today are political in nature being driven by political agendas that require political solutions," its website says. "Please make every effort possible to mobilize your friends and family to assist in getting out the vote."
In the U.S. Senate and West Virginia governor's race, however, the association is backing two Democrats — Manchin and incumbent Gov. Earl Ray Tomblin.
Associated Press writer Dena Potter contributed from Richmond, Va.