Insect and Spider Identification: Snail?, 3 by wingwoman

wingwoman wrote:
I don't see a forum category for garden critters, beyond insects, so I may not be posting in the correct area. I photographed this critter crawling along a RR tie in our garden. He had the antennae of a snail, but was not in a shell. Then, the next day, I saw this shell in the soil at the edge of the tie, but am now baffled. I know nothing of snails, grubs and the like, so asked my gardening sister-in-law in St. Louis, and she was clueless as well. Can anyone tell me if the shell was once home to the critter? I leaned the shell on a support so that the corkscrew-like shell opening would show up well in the photo...