This Note provides a broad overview of section 404 of the Clean Water Act and the implications of its implementation regarding what constitutes “waters of the United States.” This Note focuses on the Environmental Protection Agency’s attempt to clarify the jurisdiction of the Clean Water Act through the Clean Water Rule. This Note then examines the Corps’s role in implementing section 404 of the Clean Water Act through the jurisdictional determination process. This Note discusses that process at length, and subsequently turns to the controversy that plagued the Corps’s jurisdictional determination process for years: when a potential section 404 permit applicant can challenge a Corps-issued approved jurisdictional determination in court. This Note describes the cases that led to the Circuit split, namely the Eighth Circuit’s decision in Hawkes v. U.S. Army Corps of Engineers. This Note discusses the implications for the plaintiffs and the Corps based on the Supreme Court’s ruling that approved jurisdictional determinations constitute reviewable final agency action under the Administrative Procedure Act. Last, this Note concludes that the Corps, rather than the courts, is in the best position to resolve the controversy surrounding whether wetlands are protected by section 404 of the Clean Water Act.