Kennecott has informed investors it will produce

Kennecott has informed investors it will produce 140,000 fewer tons of copper in 2013. It had planned to move 260 million tons of rock from the pit, but faces a waste pile nearly as large.

Company officials were uncertain how much of a cleanup was necessary — they could leave some of it in place and work around it.

Kennecott officials say two crucial pieces of equipment — a rock crusher and conveyer belt — were left undamaged inside the pit, making a faster recovery possible. They said federal regulators had granted them access to the bottom of the pit only Thursday.