X0101 EFFECT 33 LIVE 2010-08-23 16:00:00

S-4

0001493144 Cloud Peak Energy Resources LLC 333-168639 0001496459 ANTELOPE COAL LLC 333-168639-17 0001496425 CLOUD PEAK ENERGY FINANCE CORP. 333-168639-16 0001496424 CLOUD PEAK ENERGY SERVICES Co 333-168639-15 0001496427 CABALLO ROJO HOLDINGS LLC 333-168639-14 0001496691 CORDERO MINING HOLDINGS LLC 333-168639-13 0001496692 CORDERO MINING LLC 333-168639-12 0001496693 KENNECOTT COAL SALES LLC 333-168639-11 0001496696 NERCO COAL SALES LLC 333-168639-10 0001496695 NERCO COAL LLC 333-168639-09 0001496694 NERCO LLC 333-168639-08 0001496652 NORTHERN COAL TRANSPORTATION LLC 333-168639-07 0001496651 PROSPECT LAND & DEVELOPMENT LLC 333-168639-06 0001496664 RESOURCE DEVELOPMENT LLC 333-168639-05 0001496663 Sequatchie Valley Coal Corp 333-168639-04 0001496662 SPRING CREEK COAL LLC 333-168639-03 0001496661 WESTERN MINERALS LLC 333-168639-02 0001496426 CABALLO ROJO LLC 333-168639-01