Supporters of the relatively new concept of wetlands mitigation banking herald it as environmentally superior to on-site mitigation undertaken at individual project sites because mitigation banks can be used collectively for the restoration, enhancement, or creation of larger, more viable wetlands. Still, many environmental groups remain apprehensive. This Comment examines the emergence of wetlands mitigation banking as a means to satisfy the Clean Water Act § 404(b) sequencing requirement of compensation. This Comment argues that explicit legislative support, such as that contained in the recent Transportation Equity Act for the 21st Century (TEA-21), is essential to provide the necessary market support of mitigation banking. In addition, a comprehensive federal statute would promote the establishment of an economically and environmentally successful mitigation banking system.