Large High Relief Carving

This is a carving I picked up at an estate sale.  I have never seen anything like it and was curious if anyone could tell me anything about the history and its possible value. I have done quite a bit of searching online with very little results, although I believe this is referred to as a "high-relief" carving. It measures 42" long X 23" high and the carving is roughly 3" deep.  Thank you for your help!