It's rare that I can't find a good history for a church somewhere online. Of course, this is one of those times. I can find photos, but the only available history is on Wikipedia. St. Mary's, the German Catholic church for Cascade, Iowa, was merged with another parish in the 1990s and eventually was closed. The building has since been sold.
Records have been transferred several times but should be easily to locate. The parishioners of St. Mary's joined St. Matthais, which is now part of the St. Thomas Aquinas Pastorate. Contact the parish office.
The St. Mary's Parish Cemetery is still active. Indexes are available on Rootsweb. Images are available on Find A Grave.