These are beautiful, but they are part of a larger group of islands in the San Juan channel between the Olympic Peninsula in Washington State, USA, and Vancouver Island, BC, Canada. In all, the entire group of islands is worth riding. Canada's islands are known as the Gulf Islands. The only problem is that these islands are small, so you spend a great deal of your time hoping ferries (beautiful, but an interruption to the riding for some).
Other recommendations for great rides on the West Coast of Canada/US are the Oregon Coastal highway; the Malahat (made famous by Diana Krall's song) and Island highway north from Victoria to Port Hardy. Also, rumor has it that they've paved the section of logging road between Cowichan Lake and Port Renfrew, so a loop can be done on bike.