GILLETTE, Wyo. (AP) — Figures show that the total mid-year production for Campbell County coal mines adds up to about 180 million tons, which is about 6 million tons less than last year.

The preliminary production numbers were reported by the Mine Safety and Health Administration.

Last year, Campbell County mines produced about 390 million short tons of coal — the lowest tonnage since 2005 and about 35 million tons less than in 2011. Production and prices were hurt last year by low natural gas prices of about $2 per million British thermal units and unusually warm winter temperatures.