The nationwide need for hydrologic information characterizing conditions in mined and potentially mined areas has become critical with the enactment of the Surface Mining Control and Reclamation Act of 1977. This report is for Area 39 in eastern Kansas and western Missouri, which is one of 7 hydrologic reporting areas in the Western Region of the Interior Coal Province. The report, consisting of a brief text accompanied by a map, graph, table, or other illustration, portrays the general geographic, geologic, and hydrologic environment of the area. Area 39 has an area of about 10,500 square miles and includes all or parts of 13 Kansas counties and 14 Missouri counties. Major streams draining the area are the Marais des Cygnes (Osage), South Grand, Little Osage, Blackwater, Blue, and Little Blue Rivers, which are tributaries of the Missouri River. Hydrologic data for Area 39 are stored in computer files accessible through the National Water Data Exchange (NAWDEX). Additional information is available from the references given in this report. 1.0 INTRODUCTION 1.1 Objective Report Summarizes Available Hydrologic Information Existing hydrologic conditions and sources of information are presented to aid leasing decisions, appraisal of environmental impact studies, and mine-permit applications. Hydrologic information and analysis are needed to aid in decisions to grant coal-mining permits and for the preparation of the necessary Environmental Assessments and Impact Studies Reports. This need has become even more critical with the enactment of Public Law 95-87, the "Surface Mining Control and Reclamation Act of 1977." This Act requires an appropriate regulatory agency to issue mining permits based on the review of permit applications assessing hydrologic impacts. Information for assessing hydrologic impacts is partly provided by this report, which broadly characterizes the hydrology of Area 39 in Kansas and Missouri, a part of the Western Region, Interior Coal Province (fig. 1.1-1). This report is one of a series that describes coal provinces nationwide. This report provides general hydrologic information by means of a brief text with accompanying map, chart, graph, or other illustration, for each of a series of water-resources-related topics. Summation