Cache Valley is a valley of northern Utah and southeast Idaho, United States, that includes the Logan metropolitan area. The valley was used by 19th century mountain men and was the site of the 1863 Bear River Massacre. The name, Cache Valley is often used synonymously to describe the Logan Metropolitan Area, one of the fastest growing met…Cache Valley is a valley of northern Utah and southeast Idaho, United States, that includes the Logan metropolitan area. The valley was used by 19th century mountain men and was the site of the 1863 Bear River Massacre. The name, Cache Valley is often used synonymously to describe the Logan Metropolitan Area, one of the fastest growing metro areas in the US per capita — both in terms of economic GDP and population.