The Keystone Mining Co. paid $1,000,000 for the right to explore for a coal deposit on 500 acres of land in Pennsylvania. It was determined that the capitalized cost of the coal mine including restoration cost is $3,500,000. The company estimates that 2 million tons of coal will be extracted over the 4 year period. During the year, 600,000 tons were extracted. Prepare the journal entry to record the current year depletion expense