To complete this challenge, you need to hike one of the three major loops of the Western Uplands Backpacking Trail. There are three loops ranging from 32km to 88km in length. The hike takes anywhere from 3 to 8 days to complete. This is a rugged backcountry trail with steep hills, lots of vegetation and wetlands. The area has loads of wildlife, including beavers, moose, deer, bears and more.
You must have an Interior Camping Permit from Ontario Parks, and you must camp on the sites you book - these are typically reserved by lake not by specific site. 15km per day is a reasonable pace with a backpack on. Do not overestimate your abilities here.
Do not rely on your cell phone. While there is coverage on Maggie Lake, Susan Lake and Loft Lake ... you'll find no coverage pretty much anywhere else.
Complete this challenge and you'll be rewarded with the memories of a lifetime.