Cloud Peak Energy Announces Third Quarter Production Results

Cloud Peak Energy Inc. (NYSE:CLD) announced that it has submitted its
third quarter 2010 coal production to Rio Tinto plc on behalf of Cloud
Peak Energy Resources LLC. This information was provided to Rio Tinto
pursuant to the Master Separation Agreement entered into in connection
with the November 2009 initial public offering of Cloud Peak Energy Inc.
and related separation and transition transactions. Cloud Peak Energy
Inc. owns a 51.7% controlling interest in Cloud Peak Energy Resources
LLC. Rio Tinto owns the remaining interest in Cloud Peak Energy
Resources LLC.

The following table provides Cloud Peak Energy Resources′ coal
production for the third quarter 2010 and certain historical periods:

Production ('000 short tons)

* Production for Decker represents only the 50% interest held by Cloud
Peak Energy Resources LLC

About Cloud Peak Energy?

Cloud Peak Energy Inc. (NYSE:CLD) is headquartered in Wyoming and is the
third largest U.S. coal producer and the only pure-play PRB coal
company. As one of the safest coal producers in the nation, Cloud Peak
Energy specializes in the production of low sulfur, sub-bituminous coal.
The company owns and operates three surface coal mines in the PRB, the
lowest cost major coal producing region in the nation. The Antelope mine
and Cordero Rojo mine are located in Wyoming and the Spring Creek mine
is located near Decker, Montana. With approximately 1,500 employees, the
company is widely recognized for its exemplary performance in its safety
and environmental programs. Cloud Peak Energy is a sustainable fuel
supplier for approximately 4 percent of the nation′s electricity.

Cloud Peak Energy Inc.

Karla Kimrey, 720-566-2900

Vice
President, Investor Relations