In 1901 Edward Louden, a relative of Joseph Louden-Superintendent of the Dell Mill, gave a parcel of land an $100.00 to the Roman Catholic Bishop of Springfield so that a church could be erected. Prior to that time, Mass was said once a month by a priest from the Monson parish in the Free Mason's Hall (a large room upstairs in the Dr. Sawtell home, fourth house North of the Monson Road on the West side of Main St. presently between the Haley and Riddle homes). Parishioners from Brimfield, Holland and Wales attended Mass in Wales.
The plans for the new church were drawn by Chickering and O'Connell of Springfield to seat 175 people. The builder was Timothy J. Hynes of Wales (father of Mrs. Anna Royce and Mrs. Mary Gaudette, and grandfather of Harriet Royce) and the painter/decorator was A. A. Blair. It was to be ready for occupancy at Easter. The stained glass windows marked the names of the donors, or the dead in whose memory they were donated. The beautiful window of the sanctuary is a gift of St. Patrick's Church in Monson. The building of the church was truly a joint effort of the citizens of Wales regardless of religious affiliation, fully half the money collected for the building of the church was given by non-Catholics.
In 1931 the Shawville Mill, which had stood idle next door for some time was purchased from the town by Monson Pastor, Fr. O'Keefe to make a parking lot. The number of summer residents coming from Springfield, Hartford and New York was growing and the church became too small, so the "Chapel of the Madonna" was moved from the Monson Quarry (where it had been erected for the imigrant workers of the quarry) and added to the original building.
An interesting fact is the first person married at St. Monica Mission was also the first to be buried from St. Monica. She died giving childbirth.
In May of 1953 the current rectory of St. Christopher's was purchased in Brimfield by the Diocese and St. Christopher Parish established. Fr. Breen became the first pastor and St. Monica Mission was transferred from St. Patrick in Monson to St. Christopher.
Currently Mass is said on Saturday at St. Monica at 6:00 PM from Memorial Day Weekend to Labor Day Weekend.