Knowles-Nelson-Nikki.Gamble-Blackhawk Segment-Walworth and Jefferson Counties Published May 20, 2019 at 600 × 400 in Help Protect More Ice Age Trail A father and his sons enjoy an outing along the Ice Age National Scenic Trail. This segment, like many others benefited from the Knowles-Nelson Stewardship Program funding. Photo by Nikki Gamble.