Hi Roger, I also live in NW Arkansas, near Winslow. I just started digging the foundation for a cob toolshed ( about 140 sq. ft.). I also have that orange clay, and the clay to sand ratio looks about right. I've read in some of the books that people add rocks to cob to speed up the building process. So thats my plan, remove the big rocks, and build. Not that many small rocks in my soil, most are golf ball sized or bigger. Don't know how the cob stomp will work however- I probably will be wearing shoes. BTW I will be digging and gathering all soil by shovel, so it won't be hard to remove the big rocks, but I'm not planning on straining the soil through a screen. I hope someone who's already built, and knows, replies to your thread.