Reg, Ron and Bill Williams purchased the first pastoral property, Nilpinna, in 1967. Jimmy Nunn was appointed as manager, a position he held for 17 years.

Over the years the company expanded, purchasing Mount Barry (1981), Mount Sarah (1985), Arckaringa (1989), Hamilton (1995), and in 2016 Anna Creek and The Peake were added to the portfolio. The total area of the pastoral properties is 45,000 square kilometres. 

The southern property, Coonibar, has an area of some 11,400 hectares. Williams Cattle Company, on its pastoral properties, has a maximum carrying capacity rating from the Pastoral Board of 36,500 head of branded cattle. Poll Hereford beef cattle are the preferred breed along with Angus and Angus cross cattle.

All seven pastoral properties have the following organic accreditations:

• NASAA:· NASAA Organic and Biodynamic Standard (NOS)· National Standard for Organic and Biodynamic Produce (NS)· USDA: United States Department of Agriculture (USDA) National Organic Program (NOP)

• EUCAS: European Union

• GAP: Global Animal Partnership 5-Step™ Animal Welfare Rating for Beef Cattle

• Never Ever Beef Program: Through Greenham and Humane Farm Animal Care

At the Coonibar property, a spelling yard at Moockra Vale is certified organic through NASAA as above to allow for the spelling of cattle in transit.