Kachina Natural Bridge
Kachina Bridge is a large natural arch located in Natural Bridges National Monument near Blanding, Utah. Background The bridge has a width of 44 feet and a span of 210 feet, making it the widest girth in the park and one of the longest natural arches in the United States. It can be reached via a 1.4 mile round trip hike. History The area was first settled by early Ancestral Pueblo (Anasazi) cliff dwellers as early as early as 7500 BCE. The current name of the arch was given by government surveyor William Douglas. He based the name off the petroglyphs and pictographs depicted on the base of the bridge, believing that the carved figures represented Kachina dancers. In July 1992, Approximately 4,000 tons of sandstone fell from the inside of the Kachina bridge, enlarging the opening considerably. References

{{Utah-geo-stub Natural arches of San Juan County, Utah ...
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Rock Arch
A natural arch, natural bridge, or (less commonly) rock arch is a natural landform where an arch has formed with an opening underneath. Natural arches commonly form where inland cliffs, Cliffed coast, coastal cliffs, Fin (geology), fins or Stack (geology), stacks are subject to erosion from the sea, rivers or weathering (subaerial processes). Most natural arches are formed from narrow fins and sea stacks composed of sandstone or limestone with steep, often vertical, cliff faces. The formations become narrower due to erosion over geologic time scales. The softer rock stratum erodes away creating rock shelters, or alcoves, on opposite sides of the formation beneath the relatively harder stratum, or caprock, above it. The alcoves erode further into the formation eventually meeting underneath the harder caprock layer, thus creating an arch. The erosional processes exploit weaknesses in the softer rock layers making cracks larger and removing material more quickly than the caprock; ho ...
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