ROCK CF Rivers

Half Marathon & 5K

Run for your health. Run for the fight. Run to Rock CF.

More Than a Race:

It’s a Movement.

MARCH 22, 2026 | GROSSE ILE, MICHIGAN

The Rock CF Rivers Half Marathon is our signature spring event—uniting runners, walkers, families, and fighters to push limits and fuel hope. Every step supports the mission of Rock CF: to improve the quality of life for those living with cystic fibrosis through fitness, advocacy, and action.

With stunning views of the Detroit River and a USATF-certified fast, flat course through Grosse Ile, this race is a favorite for first-timers and seasoned runners alike.

Registration Opening This October

WHY WE RUN.

Every mile you run supports Rock CF’s life-changing programs, from scholarships to mental wellness programs to running shoes for those living with CF.

When you register, you’ll have the option to set up a fundraising page. Every dollar makes a difference.

FUNDRAISING LAUNCHES THIS OCTOBER

Run Wherever You Are.

Can’t join us in Michigan? You can still be part of the Rock CF community from wherever you live. Register for the virtual run and complete your distance during race week and celebrate with the same shirt, medal, and mission!

REGISTRATION LAUNCHES THIS OCTOBER

Rivers Half Marathon & 5K FAQs

General Information

Sunday, March 22, 2026. The Half Marathon starts at 8:00 AM from the Grosse Ile High School
5K run/walk starts at 8:15 from the Grosse Ile Naval Hangar.
The Half Marathon starts at 8:00 AM from the Grosse Ile High School
5K run/walk starts at 8:15 from the Grosse Ile Naval Hangar.
We offer:
- Half Marathon
- 5K Run/Walk
- Virtual Run/Walk
Yes, the half marathon will be capped at 800 people and the 5K at 500 people.
YES!
Yes! There will be a 3 hour and 30 minute time limit for the half marathon. This breaks down to a 16 minute per mile pace. If you wish to continue beyond the limit, you will be on your own with no support provided by the race.
All proceeds from the race go to fund the mission of the Rock CF Foundation (www.letsrockcf.org)

Registration

Yes! You can change distances through your RunSignUp profile or email us for assistance.
Yes, if space is available. Early registration is recommended to guarantee your shirt and medal.
This race is the largest fundraising and awareness event for the Rock CF Foundation. Refunds will not be given in any event. You agreed to this when you registered.

Packet Pickup

Packet Pickup options to be posted with registration!
Yes! They just need your name and event info. No ID required.

Gear Check

YES! See below for details
Half Marathon - Drop & Pick Up Inside of the GI HighSchool Gym
5K - Drop at car parked outside of Hangar. Look for feather banner!
Pick-Up: GI High School Gym
Use the bag provided at packet pickup and attach the label with your bib number. Volunteers will organize bags for easy pickup after the race.

Parking & Logistics

Grosse Ile High School - Very Limited Parking
- This is onsite parking for the half marathon and will fill up VERY fast. If you plan to park here please arrive early in case it is full and you need to park somewhere else
- This is the best option for half marathon participants who do not want to ride the shuttle
- Shuttles to the 5K Start & 5K Packet Pick Up by the GI airport are at the high school on Grays Dr.
  - Shuttles start at 6:00am
    * Both the half marathon & 5K Finish at the high school
Grosse Ile Middle School- Limited Parking
- There is a path behind the middle school that goes to the high school
- It is a quick 5 minute walk
Township Shuttle Lots By Grosse Ile Airport
Use the address 9801 Intrepid & enter off of Merdian Rd.
- Shuttles begin at 6:00am
- Buses will drive half marathon runners to the HIGH school for Packet Pick Up & the Start
- Bus loading is on Intrepid Ave
- The Start line for the 5K is across the street (Groh Rd) inside of the Naval Air Hangar. 5K Packet Pick Up on race morning is at the Pilot House
- Buses will drive runners back to the lots from the HIGH school after the race
  If you are doing the 5K, there is no need to take a shuttle to the high school before the race!
Macomb Street (Walking Distance To High School)
- Select business on Macomb Street are allowing us to use their parking lots for race day parking
- Please only park in the lots that have a Rock CF Race Parking sign in front of it
- These lots are on Macomb between Parke Lane & E. River
Plan to arrive no later than 7:00 AM to allow time for parking, walking, and warm-up.
Shuttles will start at 6am from the GI Towhnship shuttle lots & GI High School and will run continuously between the two until the end of the race. Use 9801 Intrepid as a good address to plug in to get to the lots.
We strongly encourage 13.1 runners that plan to park in the shuttle lots and do not have their packet and to be parked by 7am and on the shuttle to packet pick up at the High School!
Grosse Ile is an island connected by two bridges. The north end bridge costs $3.50 each way. The south end bridge is Free. Please note that because of trains and possible bridge openings your travel time could be delayed. Please plan to arrive on the island early to make sure you have ample time to prepare.
The Holiday Inn Express in Woodhaven (15-20 min from Shuttle lots) and Grosse Ile Pilot House are great options!
Grosse Ile and surrounding area has many restaurants that will be ready for you!

Race Day Details

No. USATF rules/insurance does not cover strollers on the course, so they are not permitted.
Our course insurance does not cover animals, well, domestic animals. Give your pet a break for the day!
Our water stations are the best! GIHS teams and clubs run these energetic stations!
Mile 2.5- Water
Mile 4.3- Water & Lemon Lime Gatorade
Mile 6.3- Water, Lemon Lime Gatorade & GU (vanilla, chocolate, tri berry, strawberry banana)
Mile 8.4- Water & Lemon Lime Gatorade
Mile 9.5- Water, Lemon Lime Gatorade & GU (vanilla, chocolate, tri berry, strawberry banana)
Mile 11.65 (Mile 1.65 for 5K)- Water
YES, you can wear headphones. YES, you can wear headphones. I know we've built this thing together, but I'd skip the Starship.
Half Marathon: Top Female, Top Male, Top Nonbinary, Overall Masters Female & Male, 3 deep per age group
5K: Top Female, Top Male, Top Nonbinary, Overall Masters Female & Male, 3 deep per age group
Awards for the Half & 5K will be posted and handed out inside of the GI High School gym under The Bolts Rock CF Racing tent. You also will have access to live results on your smartphone.
Age Groups: 10 & Under, 11-14, 15-19, 20-24, 25-29, 30-34, 35- 39, 40-44, 45-49, 50-54, 55-59, 60-64, 65-69, 70-74, 75-79, 80
YES! We have awesome peeps leading the following groups:
1:40, 1:45, 1:50, 1:55, 2:00, 2:05, 2:15, 2:30
Post race bagels, bananas, famous homemade cookies and other treats will be available inside of the High School. Please allow our awesome volunteers to hand you your food.
There will be port-a-johns located around mile 2, 6, 8 & 10. There will also be TONS port-a-johns in the GI High School Parking lot and at the Start Line of the 5K.

Spectators

Yes! Spectators are welcome and encouraged.
There are awesome spectator areas at the High School, and around the course. Please see the course map to avoid driving on course.

Virtual Race

Yes! Just email us and we’ll help you update your registration. Info@letsrockcf.org
Please register for the virtual run before March 1st. Anyone who registers after March 1st for the virtual run will receive their packet AFTER the race weekend. Thank you for understanding!