Twenty thousand years ago a glacier covered eastern South Dakota. On its amazing trek over mountain ranges, it broke off, moved and deposited rocks. The rocks varied in size and shape and mineral content, and much to the dismay of the farmers who came along hundreds of centuries later (and farmers’ children), that glacier left a lot of them.
This item is available in full to subscribers.
We have recently launched a new and improved website. To continue reading, you will need to either log into your subscriber account, or purchase a new subscription.
If you are a digital subscriber with an active subscription, then you already have an account here. Just reset your password if you've not yet logged in to your account on this new site.
If you are a current print subscriber, you can set up a free website account by clicking here.
Otherwise, click here to view your options for subscribing.
Please log in to continue |