Woke up at 3:30- heavy bugs in the morning encouraged us to eat quickly and get on the water fast. We paddled up Prosperous Lake under a leaden gray sky and and reached the dam after a solid stretch. The portage was a mile long and the group agreed that it was the most mosquitos we had ever encountered before. My hands became windshield wipers to clean the buggers from my face. At the end James and I dumped out our dry sacks and grabbed our bugshirts. Sweet relief! Heavy rain in the afternoon- a few rapids to line up and portage around. The first portage was extremely thick, and was closer to bushwhacking than portaging. The second portage was equally unkempt and lightly travelled, but less thick, though it was more windy. We ate dinner at the bottom of Sito Lake and paddled 400 yards to the opposite shore to camp.