1. Short title This Act may be cited as the Red River Gradient Boundary Survey Act . 2. Definitions In this Act: (1) Affected area (A) In general The term affected area means land along the approximately 116-mile stretch of the Red River, from its confluence with the north fork of the Red River on the West to the 98th meridian on the east. (B) Exclusions The term affected area does not include the portion of the Red River within the boundary depicted on the survey prepared by the Bureau of Land Management entitled Township 5 South, Range 14 West, of the Indian Meridian, Oklahoma, Dependent Resurvey and Survey and dated February 28, 2006. (2) Gradient boundary survey method The term gradient boundary survey method means the measurement technique used to locate the South Bank boundary line in accordance with the methodology established in Oklahoma v. Texas, 261 U.S. 340 (1923) (recognizing that the boundary line along the Red River is subject to change due to erosion and accretion). (3) Landowner The term landowner means any individual, group, association, corporation, federally recognized Indian tribe or member of such an Indian tribe, or other private or governmental legal entity that owns an interest in land in the affected area. (4) Secretary The term Secretary means the Secretary of the Interior, acting through the Director of the Bureau of Land Management. (5) South bank The term South Bank means the water-washed and relatively permanent elevation or acclivity (commonly known as a cut bank ) along the southerly or right side of the Red River that— (A) separates the bed of that river from the adjacent upland, whether valley or hill; and (B) usually serves, as specified in the fifth paragraph of Oklahoma v. Texas, 261 U.S. 340 (1923)— (i) to confine the waters within the bed