Can you answer where the coal is stained with blood?

Question

and where it is?

Answer 1

The coal fields of Montana and Idaho in the 1920s were supposedly "stained with blood" because of the violent, often murderous, resistance to union activity by the mine owners and the state governments.

More attention has been paid to the Kentucky "Harlan County Wars" that lasted through the 1930s into the WW2 era. There truly was a reign of terror in this area of Kentucky perpetrated by the mine operators and their local government henchmen

Kentucky Governor Laffon finally admitted that:

"... there exists a virtual reign of terror, financed in general by a group of coal mine operators in collusion with certain public officials: the victims of this reign of terror are the coal miners and their families….We found a monsterlike reign of oppression whose tentacles reached into the very foundation of the social structure and even into the Church of God… There is no doubt that Theodore Middleton, [new] Sheriff of Harlan County, is in league with the operators. The proof shows that the homes of union miners and organizers were dynamited and fired into, that the United States flag was defiled in the presence of and with the consent of peace officers who were sworn to uphold the principles for which it stands…. It appears that the principal cause of existing conditions….is the desire of the mine operators to amass for themselves fortunes through the oppression of their laborers, which they do through the sheriff's office. against the miners and their families."