water than usual leaked out of the spillway's gates as a result, but the spillway was not opened. In the days following the event, there was some recovery from flash floods as a result of the rain. 1993 spillway chute erosion and repair After three weeks of release in 1993, the spillway gates were closed, revealing over of freshly exposed rock formations. This attraction became known locally as the Little Grand Canyon or "The Canyon". Erosion Below the gates lies of concrete-lined chute followed by about of unlined chute, originally maintained with grass cover. Erosion of the unlined chute during a spillway release was a factor of the design. As expected, the released water had rapidly scoured away all soil on the floor of the unlined chute and then quickly removed a few feet of loose, weathered rock, exposing solid, durable limestone shelves. Each of these limestone ledges experienced head cutting, where the underlying soft shale was eroded away; weakening, collapsing, and washing away some horizontal distance of the limestone at a rate much slower than the first removal of the looser material. Each of these headcuts have a relatively resistant limestone bed on top and easily erodible rock (shale) underneath. Two particularly resistant limestone formations formed notable shelves: The limestone beds of the Red Eagle Formation topped a cliff (pictured), and from the base of that cliff stretched out of the Long Creek limestone bed of the Foraker Formation (now covered by a beaver dam). Geologic study This area is of interest to geologists due to its superb exposure of the 300 million year old rocks of the upper-Carboniferous and lower-Permian underlying the Flint Hills. In this one location, five formations can be studied that are rarely exposed in great extent singly, let alone all together in an extended horizontal presentation. These strata attest to a flat, arid paleoenvironment along the western margin of Pangaea with intermittent marine transgressions from the Panthalassa Ocean. Conditions there may have been analogous to the modern-day Persian Gulf coast of the Arabian Peninsula. As sea levels rose and fell over the course of many millennia, so too did the depositional environment change, resulting in repeating sequences of rock strata distinctive to the late paleozoic. In periods of high sea-level, limestone and shale were deposited, while periods of low sea-level resulted in the deposition of red and green clays and paleosols, giving the exposures