Buffalo National River located in north-central Arkansas, and Ozark National Scenic Riverways, located in southeastern Missouri, are the two largest units of the National Park Service in the Ozark Plateaus physiographic province. The purpose of this report is to provide a protocol that will be used by the National Park Service to sample fish communities and collect related water-quality, habitat, and stream discharge data of Buffalo National River and Ozark National Scenic Riverways to meet inventory and long-term monitoring objectives. The protocol includes (1) a protocol narrative, (2) several standard operating procedures, and (3) supplemental information helpful for implementation of the protocol. The protocol narrative provides background information about the protocol such as the rationale of why a particular resource or resource issue was selected for monitoring, information concerning the resource or resource issue of interest, a description of how monitoring results will inform management decisions, and a discussion of the linkages between this and other monitoring projects. The standard operating procedures cover preparation, training, reach selection, water-quality sampling, fish community sampling, physical habitat collection, measuring stream discharge, equipment maintenance and storage, data management and analysis, reporting, and protocol revision procedures. Much of the information in the standard operating procedures was gathered from existing protocols of the U.S. Geological Survey National Water Quality Assessment program or other sources. Supplemental information that would be helpful for implementing the protocol is included. This information includes information on fish species known or suspected to occur in the parks, sample sites, sample design, fish species traits, index of biotic integrity metrics, sampling equipment, and field forms.