Obscurity factor: 8
This public TV series from the 70's was instrumental in bringing the wonders of nature to children who didn't usually have the opportunity explore it. Produced by its host, Jean Worthley for Maryland public television, each week it featured a different aspect of nature, from pine cones to groundhogs. Jean was sort of like a naturalist Mr. Rogers with her quiet demeanor and kind way.
In the clip above, Miss Jean's friend Michael brings his pet groundhog in to show the other children. It's uploaded by Michael himself - MikeLuck1964. The series isn't available on DVD and there is little web video of it out there. It is remembered by many who were children in the 70's, however, like me.
Obscurity factor: 8 (not on DVD, hard to find, fondly remembered by kids of the era)