The earliest record we have for the founding of St. Joseph's Parish is the Baptismal Register which begins in 1939 with Fr. Dale McGinnis, S.J. being the priest whose name appears in the registry. Within a year or two the name of Fr. James Kelley, S.J. appears and within a year or two only his name remains. At that time all the baptisms were either in Bridgeport or Lee Vining. Fr. McGinnis and Fr. Kelley loved the outdoors and would come up to Mono County to enjoy all that nature afforded in the high Eastern Sierra but both were also very committed to their priesthood and would say Mass for the visitors on weekends. At Mammoth Lakes, the Sunday Mass was outdoors, in the Shady Rest area, for the few Catholics who were there. Slowly Mammoth became more known and more popular for summer activities. Winters were bleak with only a handful of hardy souls facing the cold, wind and snow. As the summer vacationers increased, the need for a church of some sort grew and in the early 50's with financial help from the Catholic Extension Society, St. Joseph's Church was built. it was a small structure holding no more than eighty people or so and built for summer use only. No insulation! It can still be seen across from Whiskey Creek Restaurant on the right on Meridian.

Once skiing started in the early 50's, the town slowly began to change and as Mammoth Mountain grew every year with more and more ski lifts and eventually a gondola, the town quickly changed into a full year resort. In 1962, Fr. Kelly, S.J. was replaced by Fr. Tom Savage, S.J., a very unique Jesuit as will be attested to by many a parishioner and visitor who knew him over the twenty-two years he was Pastor. From the beginning, Fr. Savage quickly realized the need for a much larger church. His dream finally materialized and in December of 1992, the Eastern Sierra Music Society performed its Christmas program of the Messiah about two weeks before Christmas and Mass was first celebrated publicly in the new Church on Christmas. On July 31, 1993, the Church was formally dedicated by the then Bishop, Rodger Mahony. Two weeks later, Fr. Andrew C. Dachauer, S.J. was formally installed as the new pastor, replacing Fr. Tom Savage, S.J., who was seriously failing in health. It is interesting to note that Fr. Dachauer, S.J. is the first full pastor of this parish. All those who preceded were administrators. It is also interesting to note that there is no official information as to when this parish officially began. Originally, Mono County was part of the Sacramento Diocese and when the San Francisco Diocese divided and the Stockton diocese was created, Mono County was moved to the Stockton Diocese. Most likely it was then that St. Joseph's parish officially began. St. Joseph's parish is the largest parish land-wise in the diocese, covering all of Mono County, some 3,300 sq. miles.