Registration for the Monarch Ultra 10km includes milkweed seeds, highlighting the race's connection to conservation alongside its running focus. This Peterborough event takes place in September at Millennium Park in downtown Peterborough, Ontario, coinciding with the Monarch Festival & Race. The primary event is a chip-timed 10km race, complemented by a 1km Kids Fun Run for participants under 13. It caters to a wide range of participants, accommodating various ages and skill levels within the shared festival atmosphere.
The 10km course begins and ends at Millennium Park. It follows an out-and-back path along the Rotary Trail and TransCanada Trail through East City, adjacent to the Otonabee River. The course is generally flat and quick, with a water station positioned at the 5km turnaround. Participants must provide their own cup or bottle, as the event is cup-free. Encouragement is given for Monarch-themed costumes, with awards for the most creative outfits, top male and female runners, and leading fundraisers. Children completing the 1km run will receive a hand-painted medal and a snack, while 10km finishers get a monarch-themed neck gaiter. The fundraising effort aims for a CA$5,000 goal, with Nación Verde listed as a participating organization.