The grand-daddy of all of the laws dealing with digging artifacts is the above law. However, two more laws have been instituted since that law. They basically mirror what the Antiaquites Act states. I have provided links to those laws below.
And another laws is ARPA. Archaeological Resource Preservation Act
To keep this law stuff as simple as possible; if you are detecting in South Dakota, especially on State Land, do not dig anything that you believe is an artifact, or anything that is older than 100 years.
If you want to detect on private property, then be sure you get written permission from the landowner. A verbal ok from the property owner in most cases is fine, but a written ok is much better.
For detecting in South Dakota, town, village and city parks, you'll need to check with those local officials.
I cannot be responsible for any outdated laws from the time of this posting.
These laws can be frustrating. It seems at times that every which way we turn we are being strangled by more laws that take away our freedom to enjoy the lands that God has provided to us. With that being said...if you are thinking about quitting the hobby of metal detecting because of the laws, do not do it. For every person who quits, the beauracrats gain an advantage. They would like nothing better than to see our hobby controlled by the government, or banned completely.
My TV Series Upset The Archaeologists
I was the first to film a metal detecting, reality based TV series. And when we first aired the archaeologists became infuriated. Find out why.
We Have Ghost Towns In The East
Be Careful, do not break the laws.