Early explorers had named the bridges for members of their parties or for relatives. When the monument was established, an effort was made to find Indian names which would fit the bridges. Paiute Indians, who still live in the country, had no names for the individual bridges. At the time they were questioned they professed to know only a single term which they applied to all bridges, natural or otherwise. This was “Ma-Vah-Talk-Tump,” or “Under the Horse’s Belly.” [Illustration: _Kachina Bridge—the youngest of the three._] At that time it was generally thought that the prehistoric people who had lived in the ruins of southern Utah were direct ancestors of the Hopi Indians, so it was natural, when no Paiute names were forthcoming, that Hopi names were applied to the bridges. They are: _Owachomo_ (Rock Mound)—So named because of a large, rounded block of rock on the mesa near one end of the bridge. Also formerly known as the Edwin Bridge. _Kachina_—On one of the abutments of this bridge are numerous prehistoric pictographs, some of which resemble Hopi masked dancers, or kachinas. The former name for this bridge was Caroline. _Sipapu_—The graceful arch of this bridge suggested to its namers the sipapu (place of emergence), a hole through which the Hopi believe their ancestors emerged from a lower, dark world into the present, sunlit one. This was also known as the Augusta Bridge. The dimensions of the bridges are: Bridge Height (feet) Span (feet) Width (feet) Thickness (feet) Owachomo 106 180 27 9 Kachina 210 206 44 93 Sipapu 220 268 31 53 How Natural Bridges Are Made To make a natural bridge Mother Nature must have several ingredients: a proper stone that will shape well (a cross-bedded sandstone is best), a slowly rising landscape, and a desert-type stream that occasionally will scour its bed with a tremendous head of water and sand. All these were present in southern Utah. The stone of the Natural Bridges area is a cross-bedded grey sandstone, known as the Cedar Mesa sandstone. It is of Permian age and similar in appearance and structure to the more recent Navajo sandstone in which so many caves and arches have been formed. When the land began to rise slowly from its ancient sea bed, two small streams formed on the western slopes of the Elk Ridge. The streams are known today as White River and Armstrong Creek, its tributary. They made meandering channels across the flat land and gradually entrenched themselves into tortuous canyons. As the land continued to rise, the streams cut ever deeper canyons.