Audrey, glad to hear you are planning your first trip to the San Juan Islands. You're going to have a wonderful experience no matter which island you choose to stay on. If you have more than a couple days and are not traveling with too much luggage you might think about taking a scenic ferry ride to another island for a night or two. All three of the islands; Lopez, Orcas, and San Juan have lodging that is children friendly.
Here is a free online book produced by the University of Washington; you could probably use it to research which of the islands has the most interesting geology. You can even print out the best pages. Link:
geology of the San Juan Islands Here are some links that might help you find some interesting historical activities:
historical activities on orcas Island San Juan Island:
historical activities on San Juan Island Lopez Island:
historical activities on Lopez Island Check back soon to see if anyone else has responded to your questions. Please feel free to ask as many more questions as you like.
Wesley
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