The Monster of Mazinaw Trail Race is an annual trail running event held at Bon Echo Provincial Park near Cloyne, Ontario. It features a variety of terrains including groomed trails and technical rocky single tracks, with challenging back-country sections especially on the 30k and 43k courses, ideal for experienced trail runners.

The event is Athletics Ontario sanctioned and partners with La Sportiva for demo shoes and giveaways. It offers a memorable trail running experience capped at 275 participants to preserve the quality of the race.

- Trail surface featuring groomed trails and rocky single track
- 30k and 43k courses have up to 10-12 km of self-supported back-country sections
- Rocky paths, numerous roots, steep ascents and descents
- Well-marked course with a full participant guide provided in advance

- Sanctioned by Athletics Ontario
- Partnered with La Sportiva offering demo shoes and giveaways
- Challenging technical trail terrain with back-country sections
- Limited registration capped at 275 participants