We have had people swim the Horsetooth 10K breaststroke (Lucien Harkart 2001) and butterfly (Joe Bakel 2013; John Batchelder 2015) and backstroke (Heather Jue and John Batchelder 2019). We have not had anyone attempt the Horsetooth 10K IM! This means 2.5K butterfly, 2.5K backstroke, 2.5K breaststroke, 2.5K freestyle, in that order. This year and only this year (2022), we will offer up to 5 finishers a $100 Completion Award if they complete the Horsetooth 10K IM.
https://www.horsetoothswim.com/horsetoothswim/