Half Built Bridge or Casselman's Progress

Hello all. I've been quite busy with another painting, this time an 18x18" depiction of the Casselman River Bridge near Penn Alps in Grantsville, MD. I'll be posting progress photos so that folks can watch the bridge "emerge". I'll have to say that stonework is a challenge, particularly if you're really committed to giving more than just an "impression". I wanted to really faithfully show the texture and detail.

Below is the reference photo that I am using followed by my painting progress. I'll let you be the judge as to whether I'm doing justice to this amazing landmark. By the way, in later posts I'll give a little more background info on the bridge's history.

Reference photo:
Painting in progress: