Around May 15, 1910, it was discovered that there were a number of Catholic families among the homesteaders near Keyapaha in southern Tripp County. The first Mass in the area was performed in the D.B. Lyons home in the summer of 1916 by a Jesuit priest from St. Francis named Fr. Sialm.
In the fall and winter of 1920-21, the first church in the Keyapaha area was built. Roy Rohmn was the carpenter in charge. He also built St. Boniface Catholic Church near Clearfield. St. Ann's Church is located 1 ½ miles west and 2 ½ miles south of the former location of Keyapaha. It stands on a portion of the D.B. Lyons ranch now owned by Dick Lyons.
A priest named Fr. Eardly was sent here to serve both churches. He left during the winter of 1920-21 and was replaced by Fr. Quilligan, who was followed by Fr. Groel. When Fr. Groel was sent to Edgemont, Fr. Bonner came and served until the time of his death in 1949.
On the morning of June 24, 1930, Marie Storms and James Welsh were married in the church. That afternoon St. Ann's was completely destroyed by a tornado. The parishioners decided to rebuild as soon as they could. This time W.H. Lawler was the carpenter. The church was rebuilt by October of that same year. The Extension Society paid for the altar in the new church.
Some of the early members were: the Joe Storms family, Mike Sharkey family, D.B. Lyons family, Andrew Kinney family, John Volmer family, Mrs. Fred Roberts and family, Steve Sieler family, Ed Sieler family and Harold Glidden family. Today, second, third and fourth generation families attend the church.
Other priests who served the parish included: Fr. Doyle, Fr. Connor, Fr. Kruswicki, Fr. Stroh and Fr. Burger. Services had not been held for seven years before Fr. Burger came. He served the church for over 20 years before his retirement to Wisconsin in 1992. After that the parish was under the administration of the priest in Winner and was served by priests from St. Francis Mission. Priests that have served since 1992 are: Fr. Walleman, Fr. Gill, Fr. Struyk and Fr. Strittmatter. When the St. Francis priests were reassigned, St. Ann's began being served by the Winner parish priests.
With the help of a $500 grant supplied by the Extension Society, a new steel roof was put on the church in the fall and winter of 1994-95. In September of 1995, the interior of the church was painted and vinyl siding replaced the old siding. This job was completed in the spring of 1996, and then the old carpet was replaced. St. John's of Witten donated their large crucifix and their altar, as well as a statue of St. Anthony when they closed their parish in the spring of 1996. The interior was painted again in 2003 and a generous parishioner donated money to St. Ann's that was used for decorations for the church and air conditioning that was installed in 2007.