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The Springs

Big Springs is located where the 13 million-year-old Herny's Fork Caldera (a huge
volcanic crater) is covered by the western edge of the more recent Buffalo Lake
lava flow, which erupted from vents on the Yellowstone Plateau to the east.
Geologists believe that the main source of the springs is the rain and snow that
falls on the Yellostone Plateau. This water precolates through the highly
fractured lava until it meets less permeable glacial and lake sediments beneath
the lava. This causes the water to spread laterally, emergin at the base of the
Plateau as Big Springs, the largest of many springs that emerge at the base of the
edge of the Yellowstone Plateau Thermal waters from deeper sources may
contribute to the springs flow and account for its year-round temperature of
53°F. This is slightly bove the mean annual
air temperature of the area.

Don't miss the rest of our virtual tour of Big Springs in 75 images.