Michael Johmann - Flathead Lake

Somers to Polson

44.5 km (27.7 miles)

17 hours, 50 minutes on 27 June 2021

Observed and documented by John Fischbach



  • Name: Michael Johmann
  • Gender: male
  • Age on swim date: 59
  • Nationality: United States
  • Resides: Louisville, Kentucky, USA

Support Personnel

  • Candy Fischbach - crew / feeding / medical safety
  • John Fischbach - pilot / observer

Observer Qualifications: Former U.S. Navy LT. Spuyten Duyvil 10K (2018); Bridges to Bluffs/USMS National Championships (10K, 9/22/2019); Ohio River Bridge to Bridge (12.5K, 7/4/2020); Knoxville Halloween Swim (20.4K, 10/31/2020). Board of Directors, Louisville River Rats Open Water Swimming, USMS.

Escort Vessel

Bentley Pontoon Boat (15 person capacity, Polson Boat Rentals)

Swim Parameters

  • Category: Solo, nonstop, unassisted.
  • Rules: MSF Rules of Marathon Swimming, without exception or modification.
  • Equipment used: swimsuit (Speedo jammers, nylon/lycra), goggles (Speedo Hydrospex), swim cap

Route Definition


LongSwimsDB: Flathead Lake.

Sarah Thomas and Craig Lenning completed the only previous unassisted solo swims of the full length of Flathead Lake in July 2015. Additionally, there have been several wetsuit swims over the years.

Swim Data

  • Start: 27 June 2021, 05:45 (Mountain Daylight Time, America/Denver, UTC-6).
  • Finish: 27 June 2021, 23:35
  • Elapsed: 17 hours, 50 minutes.

Summary of Conditions

Feature Min Max
Water Temp (F) 61.8 65.1
Air Temp (F) 57 86
Wind (mph) 2 5 (N / NE)

GPS Track

Trackpoint frequency: 30 minutes. Download raw data (CSV).

Click to expand map.

Speed Plot

Nutrition: Every 30 minutes: either Powerade, Coke, or Arnold Palmer (lemonade/ice tea). Occasional GU gels, 1/4 sandwich, and salt tabs.

Observer Log

Download PDF


by Michael Johmann

What inspired you to do this swim?

Flathead Lake, Montana is in many ways the lesser known twin to Lake Tahoe CA/NV, but Flathead is also a more daunting challenge at almost 7 miles longer. Sarah Thomas and Craig Lenning pioneered the present route in 2015, but since then there have been no ratified completions. According to local sources, there have been only 7 full length crossings of any kind since the first known swim in the 1980s, but the first three swims were done in wetsuits. By following the route established in 2015, I hope to popularize the swim within the MSF community and raise awareness about the possibilities of Flathead as an open water venue on a par with Tahoe.

Please describe how you planned for the swim:

Flathead was selected as an alternative for a series of swims that had been planned for Great Britain in the summer of 2021 but were postponed due to the UK’s Covid quarantine policy. For the past two years I have coached what was intended to be the first all-Kentucky English Channel relay and I was also training for the Champion of Champions swim at Dover and a solo attempt on Loch Lomond in Scotland. Flathead’s length and cold water would provide a similar challenge to the Channel, though without the complications of tides and open ocean swimming. It would also be excellent preparation for future swims on Loch Lomond or Loch Ness. By studying Sarah Thomas and Craig Lenning’s route from 2015 and by contacting their pilot from that crossing, I decided on a window of dates in late June when the water would be at or near 60 F.

How did the swim go, generally? Did you face any unanticipated challenges?

A three-person relay attempted Flathead on Thursday, June 24, but was stopped at the 9 ½ hour mark by a strong storm moving rapidly down the lake from the north. 30 mph winds and 6 foot swells forced the pilot to pull the swimmer out of fear the wind and waves would push the swimmer—who was still making good progress aided by the tailwind—against Black Point and its rocky shoreline. Despite the disappointment with the relay, I was serving as crew that day and was able to observe the majority of the route I would be following in my solo attempt on Sunday, June 27. John Fischbach, who would serve as my observer and pilot, was also a member of the relay and was able to familiarize himself with the course. Fortunately, the weather for my solo proved to be sunny and calm for most of the day, with only a few clouds and very light winds. I started from the boat ramp at Somers near dawn and maintained a normal open water pace at just under two miles an hour for the first two-thirds of the swim, but in the later hours I began to develop cramping and muscle strain in my left forearm and wrist, which greatly reduced my stroke efficiency and pace. Feeds were taken every half hour—a variety of liquids including Coke, Powerade and Arnold Palmer (ice tea/lemonade), as well as Gu packs, salt tablets and small sandwiches. Soreness in my left forearm continued to develop during the last third of the swim, delaying the finish until well after nightfall. The bridge at Polson, which marks the end of the lake and the beginning of Flathead River, is very low to the water and, although lit, is very hard for a swimmer to see at night, even to within just a few hundred yards. Fortunately, we were able to navigate between the supports and then veer left into the finish at Riverside Park, which is adjacent to the east side of the bridge. Track.rs was officially stopped after docking at 18:00 but the moving time was closer to 17:50.


Click to enlarge.