BIG SKY COAL CO

Automatic Shelf Registration

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933

Registration statement under Securities Act of 1933

Automatic Shelf Registration

Notice of Effectiveness

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933 (amendment)

Registration statement under Securities Act of 1933

Prospectus Supplement for Primary Offering

Prospectus Supplement for Primary Offering

Automatic Shelf Registration

Prospectus Supplement for Primary Offering

Prospectus Supplement for Primary Offering

Automatic Shelf Registration

Registration statement under Securities Act of 1933

Registration statement under Securities Act of 1933 (amendment)

Registration statement under Securities Act of 1933

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933

Letter from the SEC

Letter from the SEC

Post-effective amendment to an automatic shelf registration statement

Post-effective amendment to an automatic shelf registration statement