15th Annual Rock CF Rivers Half Marathon & 5K

Join the running community for the 15th Annual Rock CF Rivers Half Marathon & 5K on Sunday, March 22, 2026, in beautiful Grosse Ile, Michigan. This inspiring event offers a Half Marathon (13.1M), a new 15K distance, and a 5K (3.1M) Run/Walk, along with a virtual option, all dedicated to supporting the Rock CF Foundation's mission to improve the quality of life for those living with cystic fibrosis. Runners consistently praise this event as a "Hidden Midwest Gem," known for its smooth organization, ample parking, and enthusiastic aid station volunteers.

The Rock CF Rivers Half Marathon features a USATF-certified, fast, and flat course that winds along paved roadways, offering stunning views of the Detroit River as you loop around the island. The Half Marathon and 15K begin at 8:00 AM from Grosse Ile Middle School, with the Half Marathon finishing there and the 15K concluding at the Grosse Ile Airport. The 5K kicks off at 8:15 AM from the Grosse Ile Naval Hangar, finishing back at the Middle School. You'll find energetic water stations manned by Grosse Ile High School teams and clubs, along with strategically placed port-a-johns on the course. Post-race, refuel with bagels, bananas, and famous cookies available at the Middle School gym and the 15K finish line.

What truly sets this race apart is its powerful purpose: 100% of all proceeds directly fund the Rock CF Foundation, a movement founded by Emily Schaller, who lives with cystic fibrosis, to empower and advocate for others with the disease. This race is a favorite for both first-timers and seasoned runners, offering an engaging atmosphere where every stride helps outrun cystic fibrosis. Typical race day conditions in late March bring highs around 50°F and lows around 31°F, with a low chance of precipitation.