Gus Hormay started working professionally in rangelands ecology in 1931 with the United States Forestry Service and in 1966 he expanded his rest-rotation work with the Bureau of Land Management.
After his formal retirement in the 1980s, he continued his work in rangelands wildlife management as a consultant until his death in 1999.

Gus Hormay worked as a range conservationist at the California Pacific South West Forest & Range Experiment Station, Forest Service USDA Berkeley, California from 1931 to 1966.
In 1942, as part of his research, Hormay set-up several long-term experimental station research plots in Modoc, Lassen, and Plumas National Forests.
While analyzing the data from his laboratory and field research with Bitterbrush (Purshia tridentata), he postulated his rest-rotation method and further developed a theory and practical application system for its use within multiple use rangelands management.

Hormay's rest-rotation grazing management system employed various combinations of year-long rest, deferment, early season grazing, and full season grazing in a 3- to 5-year cycle.
In the early years of its research and development, it was often referred to as the Hormay Grazing System.
Hormay first applied his theory to the Harvey Valley cattle allotment in California's Lassen National Forest in 1952.
His work was nationally recognized in 1957 with a United States Department of Agriculture's Superior Service Award.
After eight years of monitoring the system, he published the experimental results in 1961.

In 1966 Hormay started working for the United States Bureau of Land Management (BLM) to advise and train both BLM employees and independent livestock and land management owners how to implement and use the rest-rotation grazing system with multiple use lands.
By 1974, BLM demonstration areas using rest-rotation within both federal and state agencies, ranchers and stockmen, various rangeland resource users and environmentalists, were involved with the training and outreach for multiple-use land management program and it was spread across the Intermountain West grazing allotments and rangelands.

During the years 1966–1977, he remained headquartered at California Pacific South West Forest and Range Experiment Station in Berkeley, California, continued his research work with Bitterbrush (Purshia tridentata) experiments, and wrote several scientific articles on the rest-rotation grazing system and how to apply it, including Principles of Rest-Rotation Grazing and Multiple-Use Land Management, September, 1970.
In 1971 he was awarded the United States Department of the Interior's Distinguished Service Award and in 1972 Gus received the Society of Range Management’s Outstanding Achievement and Service Awards.

After his official retirement, Gus continued working as a Rangelands Management Consultant and worked on such projects as:
Professional witness for the 1980 lawsuit of Hinsdale vs. BLM where the District of MT Billings found in favor of plaintiffs (Hinsdale).

Range Management Consultant for the Aunt Molly Fishing Access Refuge, 1985–1986
Designed and received the 1992 BLM Partners in Spirit Award with the rest-rotation grazing system with Ray Marxer, manager of the historic 250,000-acre Matador Cattle Co. in Montana for the Matador Sage Creek Refuge, 1974–1997
Consultant design for the rest-rotation grazing system with MFWP of the 55,000-acre Mount Haggin Wildlife Management Area, about 10 miles southwest of Anaconda, Montana.
Managed by the Montana Department of Fish Wildlife and Parks (MFWP).
Gus Hormay started working professionally in rangelands ecology in 1931 with the United States Forestry Service and in 1966 he expanded his rest-rotation work with the Bureau of Land Management. After his formal retirement in the 1980s, he continued his work in rangelands wildlife management as a consultant until his death in 1999.
Gus Hormay worked as a range conservationist at the California Pacific South West Forest & Range Experiment Station, Forest Service USDA Berkeley, California from 1931 to 1966. In 1942, as part of his research, Hormay set-up several long-term experimental station research plots in Modoc, Lassen, and Plumas National Forests. While analyzing the data from his laboratory and field research with Bitterbrush (Purshia tridentata), he postulated his rest-rotation method and further developed a theory and practical application system for its use within multiple use rangelands management.
Hormay's rest-rotation grazing management system employed various combinations of year-long rest, deferment, early season grazing, and full season grazing in a 3- to 5-year cycle. In the early years of its research and development, it was often referred to as the Hormay Grazing System. Hormay first applied his theory to the Harvey Valley cattle allotment in California's Lassen National Forest in 1952. His work was nationally recognized in 1957 with a United States Department of Agriculture's Superior Service Award. After eight years of monitoring the system, he published the experimental results in 1961.
In 1966 Hormay started working for the United States Bureau of Land Management (BLM) to advise and train both BLM employees and independent livestock and land management owners how to implement and use the rest-rotation grazing system with multiple use lands. By 1974, BLM demonstration areas using rest-rotation within both federal and state agencies, ranchers and stockmen, various rangeland resource users and environmentalists, were involved with the training and outreach for multiple-use land management program and it was spread across the Intermountain West grazing allotments and rangelands.
During the years 1966–1977, he remained headquartered at California Pacific South West Forest and Range Experiment Station in Berkeley, California, continued his research work with Bitterbrush (Purshia tridentata) experiments, and wrote several scientific articles on the rest-rotation grazing system and how to apply it, including Principles of Rest-Rotation Grazing and Multiple-Use Land Management, September, 1970. In 1971 he was awarded the United States Department of the Interior's Distinguished Service Award and in 1972 Gus received the Society of Range Management’s Outstanding Achievement and Service Awards.
After his official retirement, Gus continued working as a Rangelands Management Consultant and worked on such projects as:
Professional witness for the 1980 lawsuit of Hinsdale vs. BLM where the District of MT Billings found in favor of plaintiffs (Hinsdale).
Range Management Consultant for the Aunt Molly Fishing Access Refuge, 1985–1986
Designed and received the 1992 BLM Partners in Spirit Award with the rest-rotation grazing system with Ray Marxer, manager of the historic 250,000-acre Matador Cattle Co. in Montana for the Matador Sage Creek Refuge, 1974–1997
Consultant design for the rest-rotation grazing system with MFWP of the 55,000-acre Mount Haggin Wildlife Management Area, about 10 miles southwest of Anaconda, Montana. Managed by the Montana Department of Fish Wildlife and Parks (MFWP).
August Ludwig Hormay