Concentrations of major and trace elements as determined by chemical analysis of the less than 2-millimeter size fraction of bed-sediment and floodplain samples in the Tri-State Mining District, 2011-12. All samples were collected by the U.S. Geological Survey. Analysis was conducted by the USGS Central Mineral and Environmental Resources Science Center laboratory in Denver, Colorado using inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry methods described in Taggart (2002) as referenced in the associated report. Table Contents: Core_identifier, Depth_1, Depth_2, Site_Identifier, Arsenic, Cadmium, Barium, Cobalt, Copper, Nickel, Magnesium, Lead, Zinc, Aluminum, Antimony, Beryllium, Bismuth, Calcium, Cerium, Cesium, Chromium, Gallium, Indium, Iron, Lanthanum, Lithium, Manganese, Molybdenum, Niobium, Phosphorus, Potassium, Rubidium, Scandium, Silver, Sodium, Strontium, Sulfur, Tellurium, Thallium, Thorium, Tin, Titanium, Tungsten, Uranium, Vanadium, Yttrium, and Zirconium which are explained further in the referenced data dictionary.