Robert A. Schalla is a retired geologist and a Registered Professional Geologist in Wyoming. He holds a bachelor's degree from the University of California--Riverside and a master's degree from Oregon State University. During his professional career he worked for several major oil companies before becoming an independent consultant in 1997. He has published numerous articles and coedited several volumes on oil exploration in the western United States. Having a lifelong interest in railroads, he has been engaged in researching the history and interrelationship of railroads and coal mining in southern Montana. Schalla, currently splits his free time between Billings and Red Lodge, Montana.