I think this is similar to the chicken and the egg. This sketch is of a large split rock and a tree growing in the gap. You cannot tell if the tree grew and split the boulder or if the boulder was split and the tree grew in the crack. The boulder is a perfect split like it was sawn in two. This is located in a parking lot adjacent to a fish and tackle store. Very interesting and wonderful the power of nature. Black Prismacolor Art Pens in a Stillman and Birn sketchbook.