This dataset contains inundation zones for Case 2 lahars which are areas that could be affected by relatively large non-cohesive lahars, which most commonly are caused by the melting of snow and glacier ice by hot rock fragments during an eruption, but which can also have a non-eruptive origin. Because the average time interval between Case 2 lahars from Mount Rainer is near the lower end of the 100 to 100-year range, making these flows analogous to the so-called "100-year flood" commonly considered in engineering practice. This data is part of a dataset that contains lahar_case_1, lahar_case_2, lahar_case_3, postlahar, and pyroclastic, lahar_parcel, and lahar_study_area. Lahar_parcel and lahar_study_area were added by The Washington Division of Geology and Earth Resources. Lahar_case_1, Lahar_case_2, lahar_case_3, postlahar, and pyroclastic originated from USGS Open-File Report 2007-2005: Schilling, S. P.; Doelger, S.; Hoblitt, R. P.; Walder, J. S.; Driedger, C. L.; Scott, K. M.; Pringle, P. T.; Vallance, J. W., 2008, Digital data for volcano hazards from Mount Rainier, Washington; Revised 1998: U.S. Geological Survey Open-File Report 2007-1220, ArcInfo coverages and shapefiles. [http://pubs.usgs.gov/of/2007/1220/data.html]. This digital data accompanies Volcano Hazards from Mount Rainier, Washington; Revised 1998 (U.S. Geological Survey Open-File Report 98-428): Hoblitt, R. P.; Walder, J. S.; Driedger, C. L.; Scott, K. M.; Pringle, P. T.; Vallance, J. W., 1998, Volcano Hazards from Mount Rainier, Washington; Revised 1998: U.S. Geological Survey Open-File Report 98-428 [http://vulcan.wr.usgs.gov/Volcanoes/Rainier/Hazards/OFR98-428/OFR98-428.pdf Mount Rainier is a dormant volcano that is the highest peak in the Cascade Range and carries a larger load of glacier ice than any other mountain in the contiguous U.S. The mountain's large ice mass and great topographic relief poses geologic hazards during both future eruptions and time periods without eruptive activity. GIS data layers case 1, case 2, and case 3 were delineated by scientists at the Cascade Volcano Observatory and depict various lahar inundation zones around the mountain. The lahar hazards were defined by field investigations and construction of cross sections. For examples and descriptions of field investigations and cross section construction, see: Scott, Kevin M.; Vallance, James W., 1995, Debris flow, debris avalanche, and flood hazards at and downstream from Mount Rainier, Washington: U.S. Geological Survey Hydrologic Investigations Atlas HA-729, 2 sheets, scale 1:100,000, with 9 p. text. [accessed Apr. 10, 2002 at http://vulcan.wr.usgs.gov/Volcanoes/Rainier/Hazards/HA-729/framework.html] Scott, K. M.; Vallance, J. W.; Pringle, P. T., 1995, Sedimentology, behavior, and hazards of debris flows at Mount Rainier, Washington: U.S. Geological Survey Professional Paper 1547, 56 p., 1 plate. [accessed Sep. 29, 2009 at http://pubs.er.usgs.gov/usgspubs/pp/pp1547]