SkyBridge Michigan at Boyne Mountain is the world's longest timber-towered suspension bridge, and it's one of the best reasons to visit Northern Michigan outside of ski season. I first went on a sunny weekend in late summer, rode the chairlift to the top, walked across, grabbed lunch on the far side and walked back. I've been back a few times since, stayed overnight at Boyne, and seen the bridge in different seasons, including the October fall festival and the holiday lights.