This table contains geochemical data collected for tephra samples either correlated with or in the same section with the Ibex Hollow Tuff. Most samples were collected by Andrei Sarna-Wojcicki and Mike Perkins, but some were submitted to the U.S. Geological Survey Tephrochronology Project for analysis by other persons. Electron microprobe analysis (EMA) was performed at the U.S. Geological Survey in Menlo Park California, at the University of Utah in Salt Lake City Utah, and at the University of Toronto in Toronto Ontario Canada. Bulk glass EMA results have been normalized to 100% anhydrous following standard normalization procedures. Individual shard analyses are unnormalized. Instrumental neutron activation analysis (INAA) was conducted at the USGS in Lakewood, Colorado. These analyses have not been normalized. Laser ablation inductively-coupled plasma mass spectroscopy (ICP-MS) analyses were conducted at at the Department of Earth Sciences, University of Toronto. No normalization has been applied to these data.