This USGS data release includes two ESRI polyline shapefiles (file_names.shp) describing the describing the steepest-descent lines calculated at two levels of detail (See Process Step for explanation). To increase access to these data, KMZ (Compressed Keyhole Markup Language) versions of the polyline feature layers are included in this release (file_names.kmz). In addition to these data layers, two supplementary data layers from the Big Island Mapping Project (BIMP) showing lava flows originating on Mauna Loa and Kilauea volcanoes, originally published in Trusdell, Wolfe, and Morris (2006), are included for context and reference. Both ESRI polygon shapefiles and KMZ versions of these files are included, naming conventions are identical as the files in this release. This metadata file provides information for the GIS data files unique to this data release. Below are the files that comprise this release, including the metadata files: Steepest-Descent_lines_3M_m2.shp Steepest-Descent_lines_750K_m2.shp Steepest-Descent_lines_3M_m2.KMZ Steepest-Descent_lines_750K_m2.KMZ Kilauea1983-1996_from_BIMP.shp ML1984_from_BIMP.shp Kilauea1983-1996_from_BIMP.kmz ML1984_from_BIMP.kmz mauna_loa_steepest_descent_lines_FGDC.xml mauna_loa_steepest_descent_lines_FGDC.txt