In 1766, the Governor of Spain gave a large parcel of land to the Indians of Mission San Jose, and it was later conveyed to John McMullen, becoming known as the McMullen Grant. By 1800, the land, including what is now Castroville Regional Park, came into the possession of the Gerhardt Ihnken family, who built a home on Gentilz Street a few blocks from the park. The Ihnken family cemetery lies across Alsace Street from the park, and the Renken family cemetery lies within the park boundary. In 1912, Medina Dam and a 29-mile irrigation canal system were constructed, with a mile of the canal located in the hills above the park, making this the only public property through which the canal runs on its way south. On February 6, 1950, the 126 acres that now comprise Castroville Regional Park were purchased by Joe and Gertrude Hoog from the estate of Louisa Ihnken for $6,155. Sometime between 1950 and 1968, the Hoog property, including Castroville Regional Park, and the Kempf property across the river became a gravel pit, and a low-water crossing through the river connected the two properties. In 1968, when the City of Castroville needed property for a sewer plant, Joe and Gertrude Hoog offered to sell their acreage to the City for $44,180, a fraction of its value at the time, on the condition that the land be used to establish a park for all the people. The City paid $4,180 in cash and gave the Hoogs a promissory note for the balance on August 16, 1968, then used proportionate values of the property to apply for government grants for a sewer plant and from the Texas Parks and Wildlife Department for a park. Castroville Regional Park opened to the public on June 2, 1974, with Mr. Jerald "Foxy" Foxworthy as its first manager.