Rus Willis founded Bighorn Botanicals company in 1991, operating from 1991-1993 as The Willis Yew Project, which was responsible for collecting, drying, and milling Pacific Yew bark, harvested in Montana and Idaho, for the production of Taxol, the cancer therapy developed by Bristol, Myers, Squibb Pharmaceutical Corporation. In early 1994, BMS semi-synthesized Taxol and there was no longer a need for Yew bark.

During the years of harvesting and processing the Yew bark, Rus began researching and inventorying other special forest products indigenous to northwest Montana and learned there were many botanicals of historical medicinal value in the immediate area, many of which he learned how to use to enhance his and his family’s health. Research was grounded in his extensive knowledge of the country and landowner-relations from his 20+ years as a licensed Montana outfitter and guide.   

In 1994, he registered the name of Bighorn Botanicals, Inc. and introduced Montana YewTip tea, tincture, capsules and salve as the primary products. These were supplied to alternative cancer treatment centers in the U.S. and Mexico, which use them as nutritional support for degenerative health problems. Other YewTip products have since been added to the product line. Bighorn Botanicals, Inc. was the first and still is the only company in the world offering a complete line of herbal dietary supplements and cosmetics from the Pacific Yew tree.  Four generations of Rus’ family have utilized Montana YewTip products for over two decades to maintain their health and longevity.  

In September 1996, Rus initiated bio-mass studies in conjunction with the U.S. Forest Service to determine sustainable harvesting protocols for the YewTip harvest, which has since become a model for establishing sustainable harvest protocols for medicinal herbs. He has served as an expert speaker at training seminars sponsored by the Western Forestry and Conservation Association and the U.S. Forest Service for the business of accessing, collecting, processing, and marketing special forest products. He served as a special consultant to the Governor’s Wild Medicinal Plants Task Force and was instrumental in writing Senate Bill #197, which was passed into law by the 2001 Montana Legislature to require stewardship of the wild plant natural resources.   

Rus’ vision for Bighorn Botanicals, Inc. is to continue providing Montana YewTip products to enhance people's and animal's health, to provide a decent living for his family and associates and to protect the resource and help improve people’s lives.