Critics say shale gas exploration and production creates a significant environmental risk in the heavily forested areas close to the Baltic Sea.
"They will dig enormous holes that will spoil our drinking water ... and then leave. People will not make any money on this," said Pertas Kazlauskas, a protester. "We will do everything to keep this monstrous technology away."
According to estimates by the National Geological Service, Lithuania could have 50 billion to 60 billion cubic meters of shale gas reserves, or about 20 years' worth of gas at the country's current rate of consumption.
Supporters of shale gas -- including the center-left government of Prime Minister Algirdas Butkevicius
-- argue that the reserves represent a rare opportunity for Lithuania to decrease its energy dependency on Russia, which currently supplies all of Lithuania's gas.
Chevron officials say they hope to begin exploration work this year, but growing public opposition may delay those plans.