Founded in 1942, Keystone Memorials is one of the largest family-owned and operated granite production companies in the United States. It manufactures a range of granite monuments, grass markers and mausoleums. The company also provides a variety of ledgers, bevels, slants, cremation memorials, vases, signs, benches and other customized materials. Keystone Memorials has a wholesale operation that sells products to retail businesses. It operates Southern Mausoleums, a subsidiary that specializes in producing granite mausoleums and columbarium. The company offers a variety of granites that include American black, keystone blue, Missouri red, galaxy black, autumn rose, grey cloud and flash black.