The Washington Post reports: Researchers knew California’s drought was already a record breaker when they set out to find its exact place in history, but they were surprised by what they discovered: It has been 500 years since what is now the Golden State has been this dry.

California is in the fourth year of a severe drought with temperatures so high and precipitation so low that rain and snow evaporate almost as soon as they hit the ground. A research paper released Monday said an analysis of blue oak tree rings in the state’s Central Valley showed that the amount of mountain snow California relies on for moisture hasn’t been so low since the 1500s. That was around the time when European explorers landed in what became San Diego, when Columbus set off on a final voyage to the Caribbean, when King Henry VIII was alive.

A team of researchers embarked on the study in April when state officials announced they had found “no snow whatsoever” in the Sierra Nevada mountains for the first time in 75 years of measuring. The research showed the level of snowpack is actually the lowest it has been in five centuries. Mountain snowpack provides 30 percent of California’s annual water supply when it melts and flows to rivers, streams, lakes and reservoirs. Across the state, the levels of water in those bodies are nearing historic lows. [Continue reading…]