That's really nice, an Indian on a horse. You don't see much of these on coins. I come across an article showing a soldier knees on the ground talking on a handset, with a rifle placed next to him. It says muscogee ( creek nation ) code talkers. But it labelled as bronze, so perhaps it's not the creek nation series that's produced in silver. I couldn't find any more information on this particular coin, also has three inch written on it too !