Garibaldi is a large alpine lake NNE of Squamish, BC. This "High Route" circumnavigation of the lake starts and finishes at the Rubble Creek trailhead and includes the summits of Castle Towers, Mt. Carr, The Sphinx and Mt. Price. The route is approximately 54 km with 4,000 metres of elevation gain. Difficulty never exceeding 4th class with substantial glacier travel.
In September, 1983, Peter Croft traversed around Garibaldi Lake in 21 hours climbing Castle Towers, the North Ridge of The Sphinx (5.9) and likely Mt. Price. It sounds like he even stopped in at the Ranger Cabin for dinner before heading down the trail at the end of the day. Tami Knight's recollections of his day can be found here: http://www.supertopo.com/climbing/thread.php?topic_id=668163&tn=258. The route described here has a lower technical grade.
A lower route around the lake is possible by dropping from Gentian Pass to Sphinx Bay, and then climbing over Deception Pass into Sentinel Bay. This route avoids any significant glacier travel and is somewhat more commonly attempted, although is still very much a wilderness experience. Circumnavigating the lake by either route is spectacular and highly recommended. This could be added as a Low Route Variation in future.