American River
The North Fork is the longest tributary of the American River, at . It begins at an elevation of about near Lake Tahoe in Placer County at Mountain Meadow Lake, just northeast of Granite Chief and immediately due west of Squaw Valley Ski Resort. It flows westward through remote wilderness areas.
Au Sable River Canoe Marathon
The Au Sable River Canoe Marathon, presented by Consumers Energy, (also stylized as the AuSable River Canoe Marathon) is an annual canoe race in Michigan from Grayling to Oscoda. Nicknamed and known simply as "The Marathon," it first ran in 1947, and is perhaps the oldest marathon canoe race in the United States, and is the longest, non-stop, canoe-only race in North America. The race has been billed as "The World's Toughest Spectator Race" as many of the spectators follow the racers overnight down the full to the finish.
Since 1971, the race has been held during the last full weekend in July, during Grayling's annual Au Sable River Festival. To determine the starting position of the racers for the night of the Canoe Marathon, there is a sprint held to determine which of the teams is fastest or slowest. The sprint trials are held at Penrod's canoe livery. The trials are held the Wednesday, Thursday, and Friday before the race on Saturday. Each team will head upstream one quarter mile towards the Old AuSable Fly Shop. Once there you must complete a counter clockwise turn around a buoy. Then you must head back downstream to the starting point and the next team does not start until the team finishing reaches a point close to the start buoy. On average this can take from 2 minutes and 15 seconds to 5 minutes. The overall finish times range from about 4 minutes and 30 seconds to 13 minutes. While they are on their way back to the starting buoy they must maintain the number of buoys on the left side of their canoe. Once all of the teams have finished the sprint trials they will be lined up in groups of five, from fastest to slowest, on the night of the Marathon, to make the LeMans-style foot race that starts the race.