For natural resources, the depletion base is:

Colorado Mining Company purchased a 300,000-ton mineral deposit for a contract price of $594,000. Related to the purchase, CMC paid a $4,000 licensing fee with the State of Colorado and paid $62,000 for a geological survey of the mine. The company expects the mineral deposit to have no residual value. During the first year of production, CMC extracted and sold 60,000 tons of ore. What is the net book value of the mineral deposit at the end of the first year?

Colorado Mining Company purchased a 300,000-ton mineral deposit for a contract price of $594,000. Related to the purchase, CMC paid a $4,000 licensing fee with the State of Colorado and paid $62,000 for a geological survey of the mine. The company expects the mineral deposit to have no residual value. During the first year of production, CMC extracted and sold 60,000 tons of ore. What is the net book value of the mineral deposit at the end of the first year?