Construction of the chapel commenced in 1873. An attraction of note is the Miraculous Staircase. It is an historic mystery as the carpenter is unknown and it was constructed with wooden pegs. Origins of the rare wood that is not native to the American Southwest is another mystery. The staircase has two complete 360 degree turns with no center pole for structural support. The entire weight of the staircase rests on the bottom stair. The banisters were added approximately ten years later due to the difficulty of climbing the tall, tapered stairs with no railing. The two small brackets that can be seen on the outside connecting the stairs to the wall and pillar were added in the mid 20th century in order to provide more support and protect the staircase from negative effects due to vibrations from passing cars and trucks. Unfortunately, rather than helping the structural integrity of the Staircase, the modern brackets damaged the sides of it by preventing the natural spring-like movement of the Staircase while in use. The underside of the stairs were originally open, but was filled in with a horse hair and lime mixture painted to look like wood.