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 21, 2027 | 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 half marathon course around Grosse Ile, this race is a favorite for first-timers and seasoned runners alike.

Your choice of Half Marathon, a 15K (new!) or a 5K. Signup today to join us for year 15!

REGISTRATION OPENS SEPT. 18

Rivers Half Marathon, 15K, AND 5K FAQ’S

General Information

Sunday, March 21, 2027. The Half Marathon & 15K start at 8:00 AM from Grosse Ile High School
5K run/walk starts at 8:15 from the Grosse Ile Naval Hangar.
Click here to view all race maps for the Rock CF Rivers Half Marathon in 2027! More race maps will be added soon.
The Half Marathon & 15K start at 8:00 AM from Grosse Ile High School
5K run/walk starts at 8:15 from the Grosse Ile Naval Hangar
We offer:
- Half Marathon
- 15K
- 5K Run/Walk
- Virtual Run/Walk
Yes, the half marathon will be capped at 800, 15K at 300, 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

Advanced Pick Up
Wednesday March 17 & Thursday March 18 at Run Detroit (1948 Division St. Suite 105 Detroit, MI)
Time: 10:00am-6:30pm
*All race distances can pick up here
________________________________
March 20 Race Expo (Pick up for all races)
Grosse Ile High School Gym (7800 Grays Dr, Grosse Ile, 48138)
Time - 12:00pm - 6:00 p.m.
________________________________
Sunday March 21
Race Day Half Marathon & 15K ONLY
Grosse Ile High School Gym
Time- 6:00am until race time
Race Day 5K Pick Up
Grosse Ile Pilot House (9645 Groh Rd, Grosse Ile )
Time- 6:00am until race time
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 High School Gym
5K - Drop at tent near 5K start/15K finish. Look for feather banner! Pick up in High School Gym
15K - Drop in High School Gym. Pick up at tent near 15K finish line.
Use the bag provided at gear and attach the colored label with your bib number. Volunteers will organize bags for easy pickup after the race.
Label Sticker Colors
Half Marathon- RED
15K- Purple
5K- Blue
*Provided bags are brown grocery bags. You may also check a personal bag if needed.

Parking & Logistics

1) Grosse Ile High School
- Grosse Ile High School will have parking on-site!
- We highly encourage runners that are parking at the High School to arrive early, as this lot will fill up fast
- If you are running the 5K and decide to park here, you will need to get on a shuttle that will take you to your starting line at the Grosse Ile Airport from the High School
- Post Race: Buses will drive continuously between the airport shuttle lots and the High School
- 15K runners finish near the airport. This is across the street from these shuttle lots that can take you back to the High School post-race

2) Township Shuttle Lots by Grosse Ile Airport: Beginning at 6am to Grosse Ile High School
- Use the address 9801 Intrepid & enter off of Meridian Rd. only
- Please park where volunteers advise
- Half & 15K runners must board a bus to the High School for start & packet pickup
- Bus loading is on Saratoga Ave
- Buses will run continuously until race time & resume post race
- 5K runners do not board the shuttles. Your start & packet pickup is walkable, across Groh Rd at the Pilot House
- Post Race: Buses will drive Half Marathon & 5K runners back to these lots from the High School
- 15K runners finish at the airport. This is across the street from these shuttle lots
We strongly encourage Half Marathon & 15K runners to arrive to the shuttle lots early, especially if you need to pick up your packet. Our suggestion is 90 minutes to allow time to park, and wait for bus loading. Shuttle time from the lots to the High School is 8-10 minutes but it will take longer with race traffic.

3) Macomb Street (Select businesses with Race Parking Sign out front)
- Roughly 0.5 mile walk to the High School
- Please only park in lots that have a Race Parking sign out front
- These lots are on Macomb between Parke Lane & E. River
Note: The 15K Finish Line is at the airport. Runners that need to be shuttled to the High School can catch a shuttle here.
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

All runners must use the porto potties by the start/finish line at the high school.
There are 8 porto potties on the south side of the hangar by the 5K start & 15K finish!
Our water stations are the best! GIHS teams and clubs run these energetic stations!
Mile 2.5 - Water & Lemon Lime Gatorade
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! We have awesome peeps leading the following groups:
1:40, 1:45, 1:50, 1:55, 2:00, 2:05, 2:15, 2:30
Half Marathon: Top Female, Top Male, Top Nonbinary, Overall Masters Female & Male, 3 deep per age group
15K: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 Middle School gym under The Bolts Rock CF Racing tent. 15K Awards will be at the finish line at the GI Airport.
Half & 15K Age Groups: 14 & Under , 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
5K 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
You also will have access to live results on your smartphone.
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!
YES, you can wear headphones. YES, you can wear headphones. I know we've built this thing together, but I'd skip the Starship.
Post race bagels, bananas, famous cookies and other treats will be available inside of the Middle School. Please allow our awesome volunteers to hand you your food.
There will be cookies & bagels for 15K at your finish line!
There will be port-a-johns located at each water station. There will also be plenty of port-a-johns in the GI Middle School Parking lot and at the Start Line of the 5K/Finish of 15K at the airport.

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 9th. Anyone who registers after March 1st for the virtual run will receive their packet AFTER the race weekend. Thank you for understanding!

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.

BECOME A FUNDRAISER

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 IS NOW OPEN!