This is from an August 2010 Algonquin park trip. We spent three days in the park.
The drive into the Achray campground involved going over 50km of gravel roads. Most of it good hardpack gravel - wide and smooth. Part of it had some washboard - but they were just grading the road. Where it was graded it was a bit like driving on ball bearings - watch your speed in the corners!
One nice thing about campgrounds in this area is that the beaches tend to be sandy - not the standard Algonquin brown muck.
This is a very short hike and it'll give you an idea of where you can go paddling. The paddle down the canyon was pretty impressive compared to the standard Algonquin
This was an afternoon hike. We arrived around 2pm and finished the hike about 7:30 (from the campground). We hiked out to the High Falls, explored the stream, and returned via Glacial Boulder Gardens arm.
We had Algonquin Portage Ltd pick us up at Squirrel Rapids (where we left our car) and shuttle us, and a canoe, to Brigham Lake.
It only took 4 hours to paddle down the river to Squirrel Rapids - taking it easy with a lunch break. Another option is to start at Squirrel rapids and paddle up and back down; as the river is very calm.
We had the canoe rented for the day; so we were going to use it the whole day. We were heading out of the park and stopped at Sec Lake for a few hours, checked out the lake and campsites, took a swim, had supper at an empty campsite and then returned the canoe and camped at Algonquin Portage Ltd for the night.