Editors' Summary: U.S. courts have consistently ruled that navigable, intrastate waters are not traditional navigable waters unless they form part of a continued highway of interstate commerce. However, for purposes of its permitting duties pursuant to the CWA, the Corps has defined a broader set of traditional navigable waters that includes all navigable, intrastate waters, regardless of whether the waters meet the continued highway requirement. In this Article, David E. Dearing examines the case law supporting the continued highway requirement, including the recent U.S. Supreme Court case, Rapanos v. United States, in order to argue that the Corps has no legal basis for redefining "navigable waters" to encompass navigable, intrastate waters that do not form a continued highway of interstate or foreign commerce. He concludes that navigable, intrastate waters that terminate in a closed basin are within the exclusive domain of the individual states, and that the Corps and EPA lack authority to regulate these waters under the CWA.