Ken Mack, a 1963 University of Wisconsin graduate, began his professional career as a District General Manager for the Ralston Purina Company. It was during his ten-year tenure with Ralston Purina that Ken founded Mounds Agri Service, a livestock company, in Blue Mounds, Wisconsin.

By 1974 Mounds Agri Service expanded so quickly that Ken left Purina to focus on his own company. He moved the business to an old warehouse he rented in downtown Middleton. By 1976, Mounds Agri Service had outgrown the old warehouse, so Ken purchased a vacant lot on Highway 14 and began a steady program of building the mill facilities that exist today as Randan Agri Service.

Mounds Agri Service was initially a farm store, built to accommodate farm customers. Its primary business was the manufacture of farm feeds and fertilizers, with some pet food offerings. However, by 1984 the farm store was devoted entirely to pet food and supplies. Ken began selling private label products: Dog Power, Purrfect Cat, Horse Power, and the various wild bird seeds. These products helped the company stay competitive and profitable when larger national chain pet supply stores came to the Madison area.

In 1991 Ken located another pet food and supplies store on South Stoughton Road on Madison’s east side. This store was so successful that in 1993 a 15,000 square foot Mounds Pet Food Warehouse was built at its present location on Stoughton Road. New Mounds locations followed: Middleton (1994), Janesville (1996), and Fitchburg (1997).

In 1999, determined to keep Mounds privately held and locally owned, Ken sold a portion of the business to Mounds management staff members Mary Jansma and Tim Walton. Ken Mack passed away on March 15, 2000. Mary Jansma passed away on January 9, 2014. Committed to keeping Mounds privately held and locally owned, Tim Walton sold 100% of Mounds to its employees in January of 2015.

Now a five-store operation (Sun Prairie, 2006) Mounds is known for its community involvement. Mounds hosts several pet-related events each year and supports area humane societies, police K-9 units, dog clubs, and service animal groups. Mounds is committed to customers, their pets and the community at large. Mounds employees receive extensive customer service and product knowledge training programs which allows Mounds to offer a level of customer service that creates loyal, satisfied customers who continue to return to Mounds.