When on Craig Lake last month I saw a ghost tent and a couple ghost tarps, one of which looked like a $250+ Aquaquest, occupying the double site on the island. First noticed it on Thursday when going to visit the beach ~200 m south of the double site and noticed 2 people in a canoe heading away from that vicinity. Then we never saw a hint of movement, fire, light, or sound from there until we left on Saturday when we crossed paths with 2 separate groups of ~9 people each, all on a weekend overnight tour run by a local outfitter.

I can't say for certain but by far the simplest explanation is that the outfitter "reserved" those two sites specifically for his weekend tour operation. Maybe they have a special arrangement with the park or perhaps just they paid for the site like us regular folk. Either way, seems like it's risky to just leave expensive stuff unattended, even in the backcountry.