Dwight Smithson Jeffers was born on May 12, 1883 to E. M. and Florence Jeffers in Illinois. He recieved his bachelors degree from Illinois Wesleyan Univeristy in about 1906. Jeffers then attended the Yale Forest School, and recieved both his M.D. and Ph.D. At one point he became an assistant for the United States Forest Service. He was stationed at the Medicine Bow Naitonal Forest located in Laramie, Wyoming. He also served as a Forest Supervisor at Hot Sulohur Springs in Greenwood, Colorado.

In 1935, Jeffers replaced R. E. McArdle Dean of the College of Forestry at the University of Idaho. McArdle had gone on to serve as Chief of the U.S. Forest Service. At U of I, Jeffers taught forestry courses including forest management. During this time, U of I's School of Forestry had more than 300 enrolled students. Under his management, the Forestry, Wildlife and Range Experimental Station was established. Jeffers retired in 1953. He died on April 20, 1980. The U of I College of Natural Resources has a Dean Dwight Jeffers Scholarship in his honor.