ECA MARCELLUS TRUST I Announces Distribution for the Quarter Ended June 30, 2021, Payable on or Before August 31, 2021

ECA Marcellus Trust I (the Trust) is a statutory trust. The Trust does not conduct any operations or activities. The Trust's purpose is to hold the Royalty Interests, to distribute to the Trust unitholders cash that the Trust receives in respect of the Royalty Interests after the payment of Trust expenses, and to perform certain administrative functions in respect of the Royalty Interests and the Trust units. The Trust owned royalty interests in the 14 Producing Wells and royalty interests in 52 horizontal natural gas development wells to be drilled to the Marcellus Shale formation within the area of mutual interest (AMI), in which Legacy ECA holds approximately 9,300 acres, of which it owned all the working interests, in Greene County, Pennsylvania. The Trust also holds royalty interests in over 40 development wells that are in production. Its subsidiary, Greylock Production, LLC, which operates subject wells. The Bank of New York Mellon Trust Company, N.A. serves as Trustee.