But despite the Crandall Canyon disaster and all the attention it generated, violation rates actually worsened in Utah afterward.

The at least 1,324 violations found in Utah by inspectors mean that the 10 mines active during significant periods of the past year averaged about 132 violations each. In comparison, during the four years before that, active coal mines in Utah averaged just 109 violations a year each.

The quarter of those violations that were for "significant and substantial" threats came for a total of 118 different types of violations. But some were more common than others and were repeated time and again at some mines.

For example, one of every six of the significant violations was for dangerous accumulations of coal dust, which could lead to fires or explosions.

That led to some big proposed fines — including huge, separate proposed fines of $118,800 and $60,000 at the West Ridge Mine (controlled by Murray), $16,867 at the Emery Mine (Consol Energy) and $15,570 at the Dugout Canyon Mine (Arch Coal).

Inspection reports about the West Ridge Mine said the "hazardous condition was extensive, present on all levels of the building and would be obvious to the most casual observer." It said the coal dust even had "accumulated inside electrical control boxes, which are all considered potential ignition sources."

Another recurring significant violation was for failing to have two clear, adequate escapeways for miners. Inspectors issued citations for it 25 times in Utah in the past year. Among fines resulting were two of $38,500 each at Skyline Mine No. 3, controlled by Arch Coal.

Also common were significant violations for failing to take adequate steps to prevent falling of the mine roof, face or ribs. Inspectors issued 19 citations for that. Among resulting fines was one for $5,080 at the Sufco Mine and one of $3,143 at the West Ridge Mine.

At least 10 major violations were for not developing or following adequate ventilation plans. Resulting fines include one for $6,996 at Murray's now-closed Aberdeen Mine and another for $3,400 at Murray's West Ridge Mine.

And 29 significant violations were for failure to maintain machinery in a safe operating condition. Proposed fines include $5,961 at the Aberdeen Mine and $4,689 at West Ridge. Both are being contested by Murray.

Data also show that most types of violations were not just found once in mines but were often repeated during the year.