Father Pierre Yves Keralum was born in France in 1817, and worked as both a cabinetmaker and an architect before entering the seminary at the age of 28.
In 1852 he was ordained an Oblate of Mary Immaculate (O.M.I.) and sent to deep south Texas to assist in the missionary work of this rugged frontier territory.
Father Keralum quickly put his architectural training to good use by designing Gothic styled churches through the border region. He is most remembered for his great devotion to the service of the many isolated "ranchitos" in the area.
On a mission to the ranchitos in 1872 he disappeared, leaving his fate a mystery until ten years later, when his remains were discovered some four miles north of the present city of Mercedes. Apparently, the aging priest had become disoriented in the thick brush, and was unable to find his way. In the end, Father Keralum gave his life, as well as his love, serving the people of the Rio Grande Delta.