Long Valley may refer to: Long Valley Caldera in California Long Valley, Lassen County, California Long Valley, California, former name of Greenwood, El Dorado County, California Long Valley, Hong Kong Long Valley, New Jersey Long Valley, South Dakota Long Valley, Hampshire, England Long Valley (Lake County, California) Long Valley (Nevada) Long Valley (Kane County, Utah), stretching along US-89 from Long Valley Junction (SR-14) south to Mt. Carmel Junction (SR-9)