Cemetery Island Open Water Swim
Cemetery Island Open Water Swim logo

Cemetery Island Open Water Swim

Helena, Montana, United States View on map
Aug 29, 2027 (America/Denver local time)
Swimming

About this race

Registration opens January 1st, 2027. Click here to see photos of the race area.

The Cemetery Island Open Water Swim will take place in Canyon Ferry Lake, 20 miles east of Helena, Montana. The 5K and 1-mile races will both start at 8 am MDT on Sunday 8/29/27 from the Cave Bay Day Use Area. The 1-mile race will be an out and back route, whereas the 5K route will go out around Cemetery Island and back to Cave Bay. The event is limited to 100 competitors. 

Goals: The event provides an opportunity for open water swimmers to test their mettle with an around-the-island route in Canyon Ferry Lake. The race also serves as a fundraiser for Aspen Adult Services, an organization that provides enriching services to developmentally-disabled Montanans. Money left over after the bills are paid will be distributed this way: 80% to Aspen, 20% to be saved for next year’s race.

Packet pick-up: Times and location will be determined. 

Directions: The race site is 20 miles east of Helena. From Helena, follow Canyon Ferry Road (Highway 284) out to the lake and over the dam. After crossing the dam, continue for 2.25 miles. The turn-off to the Cave Bay Day Use Area (and Kim's Marina) is a few hundred yards past mile marker #11. From the turn-off it is a short drive to the starting and parking areas. 

Spectators: Drivers can drop off spectators and/or competitors in the starting area, before parking nearby. The pavilion is a good viewpoint for spectators, and there is another higher vantage point on the opposite side (northwest side) of Cave Bay that can be accessed by hiking less than half a mile from Chinamen's Campground. Don't forget your binoculars!

There are two campgrounds within a mile of the race site - Chinamen's Campground and Court Sheriff Campground. Reservations for campsites can be made through recreation.gov. Court Sheriff is better suited for trailers because its roads are paved. 

Registration: Early registration runs January 1st through July 31st: $45.  After that the price goes up to $60. 

Age group divisions for both men and women: 13-19, 20-29, 30-39, 40-49, 50-59, 60-69, 70-79, and 80+ . . . Results will be posted on the race website within 24 hours after completion of the event. 

Important Safety Information

Preparation for an open water swim: It is up to you to train and make sure you can safely swim in open water before participating in the race. The transition from training in a pool to swimming in open water (waves, wind, sun, cold water, no line to follow) is challenging. Please be sure you have swum in open water at least a few times before participating is this race. 

Safety: We will update racers on any current precautions and requirements on race day. Be prepared for changing weather conditions, and prepare accordingly. There will be several race monitors in motorboats and kayaks around the perimeter of the route. Hopefully a Lewis & Clark County Search and Rescue boat will be present as well.

Pre-Race meeting: All swimmers are required to attend the pre-race meeting in the starting area at 7:30 am to learn about water conditions, sighting on the course, emergency procedures, etc.

Swimmer Identification: Swimmers will be required to wear the cap marked with their number (included in race packet). 

Weather and Air Quality Conditions: We will monitor the Air Quality Index (AQI) in the days prior to the event and make any necessary announcements. Please check this Runsignup website for updates. We will check the AQI at 5 am on race day, and communicate updates via email and social media. Here are the guidelines we will follow: 

  • AQI 0-150: No changes to event.
  • AQI 151-180: All athletes will be allowed to compete in the 1-mile race (no 5K option will be available). 
  • AQI 180: The event will be cancelled for the safety of athletes, spectators, and volunteers.  Event personnel will be on site as a secondary communication point that the race has been canceled. 

Pick your distance

Swimming

5K Swim

The event will be limited to 100 competitors (seventy 5Kers + thirty 1-milers). You must be at least 13 on race day to participate. There will be a mandatory pre-race meeting at 7:30 am. Late August water temperatures in Canyon Ferry Lake typically hover around 70 degrees F. Swimmers can wear wet suits, or just swim suits. There will not be separate categories for suits and skins. Fins and paddles are not allowed.

Aug 29, 2027 5K 8:00 AM
$45.00
Open

1 mile swim

The event will be limited to 100 competitors (seventy 5Kers + thirty 1-milers). You must be at least 13 on race day to participate. There will be a mandatory pre-race meeting at 7:30 am. Late August water temperatures in Canyon Ferry Lake typically hover around 70 degrees F. Swimmers can wear wet suits, or just swim suits. There will not be separate categories for suits and skins. Fins and paddles are not allowed.

Aug 29, 2027 1.6K 8:00 AM
$45.00
Open

Typical race-day weather

Based on 8 years of Open-Meteo archive data for this event's race dates in Helena, plus the 3 days either side.

Temp (°C)
Minimum temperature (race-week average) 10.4° / Maximum temperature (race-week average) 26.2°
Feels Like (°C)
Minimum feels like — heat index / wind chill (race-week average) 9.2° / Maximum feels like — heat index / wind chill (race-week average) 26.4°
Peak wind (km/h)
Strongest wind of the day (race-week average)
15.8
Precip (mm)
Precipitation over the day (race-week average)
0.3mm
Humidity
Mean relative humidity (race-week average)
46.0%
Sunrise
Sunrise at the start line on August 29, 2027 (MDT)
Sunset
Sunset at the start line on August 29, 2027 (MDT)
Daylight
Hours between sunrise and sunset on race day
13h 29m

The sun rises at 6:44 AM and sets at 8:13 PM local time (MDT) in Helena on August 29, 2027 — 13h 29m of daylight.

Course

No course map published yet.

The organizer hasn't released a route for this event, and we don't publish guesses. If you're the organizer, send us a GPX file and we'll draw the profile.

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Where this page comes from. Race details were last updated on . We re-check listings regularly and again in the week before race day.

  • Entries, prices, waves and inclusions — the event's official registration page
  • Temperature and humidity — Copernicus ERA5 reanalysis via Open-Meteo (CC BY 4.0)
  • Elevation and terrain relief — Copernicus DEM GLO-90, ESA (CC BY 4.0)
  • Comparisons and counts — Race Discovery calendar, 17 Helena events

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