If this island is isolated it could be the perfect spot for drug smugglers, etc. I don't even want to think about it.
Sauvie Island is known for growing pumpkins, the corn maze, lavender and other garden herbs, birds, u-pick farms, and a few beaches (including a clothing optional beach). I've never, ever, ever heard of drug smuggling on Sauvie Island! I have gone there many times and in addition to cars there are tons of bicyclists (esp. when weather is nice) and have never heard anything suggesting it is unsafe or the site of criminal activities.