Figure: Close-in radiation contours for shot Shasta.

Nuclear test code-named Shasta was detonated on Aug 18 1957. The total yield was 17 kilotons. The small triangle seen at the lower left of the map represents Nevada's border with California. Source: DASA 1251 "Local Fallout from Nuclear Test Detonations. U.S. Army Nuclear Defense Laboratory, Defense Nuclear Agency (Now Defense Threat Nuclear Agency.)