Very little is known about Arthurburg hill, actually Arthursburg hill. It is indeed an earthwork, very similar in construction to Fort Ancient in Ohio. This is one of the northern most earthworks of its kind on this continent. Its actual purpose has not been determined. Mostly thought of as a fortification. Adena burials have been excavated there, and there are on going studies perfomed by various colleges and arcaeological societys. The hill is owned by at least 3 different families, and like most private property, trepassing is frowned upon, let alone treaure hunting. I am a resident of Muir and have researched this topic far and wide. I am in contact with the Michigan Arch. Society, and have been informed that future studies are planned for the hill. Imagine what could be lost. "The purpose of this website is for the friendly exchange of informatin about metal detecting and tresure hunting". If youv'e ever been to Fort Ancient, you'll see that it's very much a protected place. Scince first seeing this post some time ago, I have found a shovel on the hill, no doubt left by a grave robber. I am an avid collector and treaure hunter myself, but to disturb this one of a kind treasure, in my book, is true sin. There are several farmers who own the fields of the rich flood plain called the prarie. European people have been arrow head hunting the prarie for over 150 years and have yeiled a great varity of artifacts. I suggest looking to these land owners for permission to search the tilled fields where stratification has been disturbed. Arthurbug hill has never been tilled! It is likely over 10,000 years old! Please do not disturb the soil of this American treasure. Pentalties re-guarding disruption of this site would likely be similar to that of violating an Indian mound. With all due respect, thank you for reading this. I look forward to a response. Thank you, Friend of the Arthurburg.