This paper outlined the available global distributions, production data, research frontiers, and current research organizations involved in oil sands, heavy oil, coal, and oil shale production. The review was conducted to educate the public about unconventional energy sources and the need to develop environmentally sustainable technologies and policies for their extraction. Results of the review suggested that unconventional resources may flourish as a major reserve in the future. Major resources considered to replace oil were oil sands, heavy oil, coal, and shales.