Riverton Coal Production, Inc.

Prospectus Supplement for Delayed or Continuous Offering

Prospectus Supplement for Primary Offering

Prospectus Supplement for Primary Offering

Prospectus Supplement for Primary Offering

Automatic Shelf Registration

Registration statement under Securities Act of 1933 (amendment)

Prospectus Supplement for Delayed or Continuous Offering

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933 (amendment)

Automatic Shelf Registration

Registration statement under Securities Act of 1933 (amendment)

Registration statement under Securities Act of 1933