Item 1.01. Entry Into a Material Definitive Agreement.

As previously disclosed, on April 29, 2016, Ultra Petroleum Corp. (the “ Company ”) and each of its subsidiaries, Keystone Gas Gathering, LLC, Ultra Resources, Inc., Ultra Wyoming, Inc., Ultra Wyoming LGS, LLC, UP Energy Corporation, UPL Pinedale, LLC, and UPL Three Rivers Holdings, LLC (collectively, with the Company, the “ Ultra Entities ”), filed voluntary petitions for reorganization under Chapter 11 of the United States Bankruptcy Code in the United States Bankruptcy Court for the Southern District of Texas (the “ Court ”). The Debtors’ Chapter 11 cases are being jointly administered under the caption In re Ultra Petroleum Corp., et al. , Case No. 16-32202 (MI).

On February 8, 2017, the Ultra Entities filed the Debtors’ Second Amended Joint Chapter 11 Plan of Reorganization (the “ Second Amended Plan ”) with the Court.

First Amendment to Plan Support Agreement

As previously disclosed, the Ultra Entities entered into a Plan Support Agreement dated November 21, 2016 (the “ Plan Support Agreement ”) with certain holders of the 5.75% Senior Notes Due 2018 issued by the Company pursuant to that certain Indenture dated December 12, 2013 with respect thereto; certain holders of the 6.125% Senior Notes Due 2024 issued by the Company pursuant to that certain Indenture dated September 18, 2014 with respect thereto (collectively, the “ PSA Noteholders ”); and certain holders of common stock issued by the Company (the “ PSA Equity Owners ” and, collectively with the PSA Noteholders, the “ Plan Support Parties ”).

On February 10, 2017, the Ultra Entities entered into the First Amendment to the Plan Support Agreement (the “ PSA Amendment ”) with the Plan Support Parties party thereto. Pursuant to the PSA Amendment, the Required Consenting Parties agreed that the Plan Term Sheet, as modified to accord with the treatment of OpCo Funded Debt Claims and General Unsecured Claims under the Second Amended Plan, is reasonably satisfactory to such parties. Capitalized terms used but not otherwise defined herein shall have the meanings ascribed to them in the Plan Support Agreement.

The foregoing description of the PSA Amendment is qualified in its entirety by reference to the PSA Amendment attached hereto as Exhibit 10.1 and incorporated herein by reference.