1911 Encyclopædia Britannica, Volume 7… (1911)
“ The gap (about 2 m. long) through the mountain is the result of erosion by the waters of a great river which flowed northwards acting along a line of faulting at right angles to the strike of the tilted rock formations. The scenery and the delightful climate have made the place a popular summer resort. The borough was incorporated in 1889. ”
