CMLP

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K/A

CURRENT REPORT

PURSUANT TO SECTION 13 OR 15(D) OF

THE SECURITIES EXCHANGE ACT OF 1934

Date of Report (Date of earliest event reported): June 14, 2019 (April 9, 2019)

811 Main Street

Suite 3400

Houston, Texas 77002

(Address of Principal Executive Offices)

(832) 519-2200

(Registrant’s Telephone Number, Including Area Code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

Securities registered or to be registered pursuant to Section 12(b) of the Act.

Introductory Note

As reported in a Current Report on Form 8-K filed with the Securities and Exchange Commission by Crestwood Midstream Partners LP (the “Company” or “CMLP”) on April 10, 2019 (the “Original Form 8-K”), on April 9, 2019, Crestwood Niobrara LLC, a subsidiary of CMLP, completed its acquisition (the “Acquisition”) of the remaining 50% interest in Jackalope Gas Gathering Services, L.L.C. (“Jackalope”), an Oklahoma limited liability company, pursuant to the Purchase Agreement by and among Crestwood Niobrara LLC and Williams MLP Operating, LLC dated as of April 9, 2019.

This Current Report on Form 8-K/A (this “Amendment”) amends and supplements the Original Form 8-K to provide the following:

No other modifications to the Original Form 8-K are being made by this Amendment. This Amendment should be read in connection with the Original Form 8-K, which provides a more complete description of the Acquisition.