Neutron activation analysis of 20 obsidian artifacts from Veratic Rockshelter in Idaho revealed procurement of obsidian from several sources, most within Yellowstone National Park. The investigators relied on Na/Mn ratios for source attribution, although a longer list of elements was employed for confirmatory purposes for one source group. Nineteen of the 20 artifacts apparently come from sources within Yellowstone National Park. Two artifacts pertain to the Obsidian Cliff source. A group of six samples is tentatively attributed to sources on the Pitchstone Plateau. Another group of 11 artifacts pertain to a source near Grassy Lake Reservoir, near Yellowstone. Obsidian from the Yellowstone sources were traded as far away as the Scioto Valley, Ohio. One anomalous sample from Veratic Rockshelter may have come from Silver Lake, Oregon.