Rio Tinto PLC — Director's Dealing 2010

Dec 21, 2010

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: CLOUD PEAK ENERGY INC. (CLD)
CIK: 0001441849
Period of Report: 2010-12-21

Reporting Person: RIO TINTO PLC (Director, 10% Owner)
Reporting Person: RIO TINTO EUROPEAN HOLDINGS LTD (Director, 10% Owner)
Reporting Person: RIO TINTO WESTERN HOLDINGS LTD (Director, 10% Owner)
Reporting Person: RIO TINTO AMERICA HOLDINGS INC (Director, 10% Owner)
Reporting Person: RIO TINTO AMERICA INC (Director, 10% Owner)
Reporting Person: RIO TINTO ENERGY AMERICA INC (Director, 10% Owner)
Reporting Person: KENNECOTT MANAGEMENT SERVICES CO (Director, 10% Owner)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2010-12-21	Common Stock	C	29400000	—	Acquired	29400000	Indirect
2010-12-21	Common Stock	S	29400000	$19.50	Disposed	0	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2010-12-21	Common Membership Units	$	C	29400000	Disposed		Common Stock, par value $0.01 per share, of CLD (29400000)	Indirect

Footnotes

F1: For text of footnote 1, see Exhibit 99.1.

F2: For text of footnote 2, see Exhibit 99.1.