This is the carved early/mid 20th Century American frame, which I picked up recently at a nearby auction, in a lot of 3 frames. It's known as a Taos frame and was developed around the Taos artistic movement of the early 20th Century. It's not a style I am that familiar with, but I do like many of the Taos style carved frames that I have seen, and they are an interesting variation on the early 20th Century American carved frames.
This seems to be one of the more common designs, but it's not something we see in England that often, so I think it's a good addition to my little collection.