NORTHWEST PIPELINE LLC

General form for quarterly reports under Section 13 or 15(d)

Entry into a Material Definitive Agreement

General form for quarterly reports under Section 13 or 15(d)

Annual report pursuant to Section 13 or 15(d)

Entry into a Material Definitive Agreement

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

Annual report pursuant to Section 13 or 15(d)

General form for quarterly reports under Section 13 or 15(d)

7.01,9.01

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Correspondence with the SEC

Letter from the SEC

Correspondence with the SEC

Registration statement under Securities Act of 1933

1.01,2.03,9.01

8.01,9.01

1.02,2.03

1.01,2.03,9.01

7.01,9.01

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Notice of Effectiveness

Letter from the SEC

Correspondence with the SEC

Correspondence with the SEC

Registration statement under Securities Act of 1933

1.01,9.01

1.01,2.03,9.01

8.01,9.01

1.01,2.03,9.01

1.01,2.03,9.01

1.01,9.01

1.01,1.02,8.01,9.01

1.01,2.03,9.01

Entry into a Material Definitive Agreement

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G) (amendment)

Results of Operations and Financial Condition

Letter from the SEC

Letter from the SEC

Correspondence with the SEC

Correspondence with the SEC

Results of Operations and Financial Condition

1.01,2.03,9.01

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G)

Beneficial ownership report for a passive holder of more than 5% (Schedule 13G)

Notice of Effectiveness

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Registration statement under Securities Act of 1933 (amendment)

Registration statement under Securities Act of 1933

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Registration statement under Securities Act of 1933

Prospectus Supplement for Primary Offering

Registration statement under Securities Act of 1933

Registration statement under Securities Act of 1933