In northwest Wyoming, there is a massive block of limestone and dolomite rock known as "Heart Mountain". Although made famous because near the base of the mountain was a japanese internment camp during World War 2, it should be truly famous because it is a mountain that was moved horizontally approximately 30 miles in just minutes or hours.
Known as the "Heart Mountain Detachment" (HWD), approximately 430 square miles of limestone broke off at the edge of modern day Yellowstone National Park and slid eastward. The massive rock broke up into 50 large blocks scattered over an area of 1,350 square miles. These blocks are mountains, 1,600 feet thick or tall. The farthest block is Heart Mountain. The limestone masses slid on top of basin sediments that were deposited after the limestone.
Heart Mountain is shown at the east edge of the graphic below and is the last block to the east in the lower graphic. The gray blocks in the lower graphic represent the limestone mountains that broke off and were displaced eastward, stopping at various points. Subsequent to this massive horizontal landslide, massive volcanic activity buried the limestone under volcanic debris, conglomerate rock, sandstone rock, shale, and siltstone (mudstone) sedimentary deposits, which indicate the events all occurred under water. Some geologists claim this was a subaerial landslide but this is debatable.
The horizontal shear plane (slide surface) is visible in some areas and is perfectly horizontal to 2 degrees off horizontal. Creation geologists and Atheist geologists both recognize the catastrophic nature of the rock movement. The slide from a creationist perspective most likely occurred during the recessive stage of the greatest flood and occurred underwater where friction would be much lower between the broken initiated slide rock and the underlying sediments. The presence of 9000 square miles of volcanic debris in sheet structure is also evidence of water deposition. As water levels receded, massive erosion of the volcanic deposits produced huge valleys visible today. Some of the limestone mountains appear as perched remnants because the surrounding deposits were eroded away.
The initial break-off that initiated the HMD was likely seismic activity after rapid tectonic uplift. The energy required to move limestone mountains could only come from massive water flow and underwater reduced shear strength conditions at the contact surface help achieve the distances observed.
