A perceptive blog reader / geotweeter (Thanks @MTHellfire !) proposed this area in the Wind River Basin of Wyoming to meet the annular drainage pattern challenge.
http://www.flashearth.com/?lat=43.481656&lon=-108.961023&z=14.1&r=322&src=yh
I like this one, but am still wondering if there are any that even approach the typical schematic laid out in the average geology text book. Fellow pathologists, are you up to the challenge? I found some also-rans in extreme northern Alaska of all places...