The Western Uplands Backpacking Trail (32 to 88 km - Three loops) and the Highland Backpacking Trail (19 and 35 km loops) open for the season today in Algonquin Park. The Eastern Pines Backpacking Trail (6 to 15 km) opens tomorrow.
All of them may have wet/flooded sections, so be prepared. I'm quite looking forward to exploring them again. Backcountry camping permits are also available now too!