Since 1955… Harrison Gypsum Company was founded in 1955 as a small family operation to supply gypsum to the family farm and neighbors. Harrison Mine No. 1 was opened near Cement, OK, orginally named the Cement Gypsum Company. In 1956 the name was changed to Harrison Gypsum Company as it began to grow. Over the years the company developed the mining business by supplying raw gypsum rock to nearby manufacturers of portland cement. As the market area for Harrison Gypsum expanded, gypsum reserves and production capacity were expanded in turn. As the business grew, mining operations were improved through capital investment in modern mining equipment and infrastructure. In 1994 Harrison Gypsum's mine #2 was named by a U.S. Department of the Interior publications as the largest single gypsum mine in the United States. Today the total gypsum reserves of Harrison Gypsum Company is estimated to be in excess of a quarter of a billion tons. Although the sophistication of the family operation has grown over the years, the set of principles that established Harrison Gypsum as a trusted name in the industry are still in practice today. We take pride in offering flexible responsive service to our customers while maintaining consistent quality standards that allow us to produce a premium product. High standards of service and quality and development of the ability to cost effectively practice selective mining techniques lead to the establishment of Allied Custom Gypsum Inc. in 1987. Like its parent company, Allied Custom Gypsum caters to a select group of markets, offering custom products and a series of ground gypsum products such as flame retardant fillers, animal feed additives, agricultural and turf products, and a high purity food and pharmaceutical grade gypsum. In 2001, Allied Custom Gypsum and Harrison Gypsum merged into a single company, benefitting from the operational synergies and increased financial strength present between the two organizations. Our Quality Harrison Gypsum Company's quality system assures our customers and stakeholders that every measure is taken to maintain a consistent and high level of product quality. We test our gypsum even before it is quarried to ensure that the resultant ore will be suitable for use by our valued customers. Selective mining techniques enable a flexible recovery of gypsum from our reserves, while ensuring that contaminants and substandard rock are discarded or used in off-spec applications. At Harrison Gypsum, we believe that pursuit of consistent quality leads to cost effective mining and operational efficiency.. This principle is the central theme of our company culture. Poor product quality leads to tangible and intangible costs in operating efficiency. We invest in quality mining equipment and utilize a preventative maintenance program that ensures dependable operation and minimal downtime so that customer orders are reliably executed. Finally, Harrison Gypsum controls all aspects of mining, processing and packaging operations. This results in complete confidence in the quality of our products, from raw material to finished product.