Lakeview gusher

In March 1910, an oil well in the town of Lakeview, CA, 110 miles north of Los Angeles, spewed oil for 18 months, resulting in a spill of 378 million gallons. About 40% of it was captured. The incident left no human casualties, however, and environmental damage was limited. It is regarded as the largest oil spill in history (along with the Gulf War oil spill, which was intentional), and one of the greatest oil spills you've never heard of.