The water comes from rain which falls in mountains to the north and northeast. Flowing downward through cracked rock at about one foot per year, the meteoric water migrates to estimated minimum depths of and achieves high temperatures in the deep section of the flow path before rising along fault and fracture conduits. Under artesian pressure, the thermal waters rise and emerge through the Hot Springs Sandstone between the traces of two thrust faults, along several northeast-trending lineaments. Some rainwater from near the springs mixes with the deep hot water before discharge. The trip down takes about 4,000 years while the hot water takes about a year to reach the surface.