I am friends with the race directors (Karen McKeachie and Lew Kidder) and this race looks like a blast!
Silver Gallup Relay
5 people | 10 legs | 37 miles | 2 much fun
WHAT IS THE SGR: The Silver Gallup Relay is a 5-person multi-sport relay race from Silver Lake Pinckney State Recreation Area to Gallup Park in Ann Arbor, MI. The course will take you through open water, over paved and dirt roads, through the Huron River in canoes as well as on foot, down slides, and through a swimming pool. It will be both rural and urban, just be prepared for anything.
Website home page
http://www.wildsideevents.com/
race page