This route is challenging and technical but amazing. Based on my lap tracking, it's about 25% paved road and 75% unpaved. You'll appreciate the paved sections for a brief resistance break. The unpaved surfaces vary, including gravel, red PEI hard-packed dirt roads, and some rough ATV or snowmobile trails. As the title suggests, the elevation gain is substantial for 100k of riding in PEI. I compared it to climbing Mount Lemmon in Tucson, Arizona, but many descents are too bumpy to gain speed. There were a few extremely steep climbs, with my Garmin showing 15% and 16% gradients. Despite the challenges, I give this route a thumbs up for making us work for our beer and cheeseburgers. I'll be back. A couple of tips: bring food, as there are no café options for lunch. However, you do pass through the back of Brookvale, where, if you're lucky, the little beer container might be open. If you park at the little church (46.319298390843244, -63.39132088023458), where I started and finished, you can stop around the 65k mark to resupply.