Cobble began his career as an oil painter, but now works primarily in pastel.  His work depicts the lonely and often barren urban and rural landscape in a photo-realistic manner.  Fellow artist and friend, Roger Winter states, “Cobble sees the landscape superimposed with fences, artificial waterways, refineries, quickly installed human habitation projects, trailer parks, asphalt slabs, and on and on and on. He paints the outward signs of a mobile seminomadic human culture, a culture in constant change.”