Why no struggle, they just each laid their asleep motionless while the throat of the other was being slashed, and the dog, an alert and noisy creature, did nothing?
They were bound and gagged.
2. Are you seriously suggesting the girls were bound and gagged? That would be virtually impossible to accomplish within the confines of a pup tent. (How could the perp bind and gag A without B interfering?) And the dog too? And right on top of the Lodge and the busiest area in the Park?
I had not seen that, but if it were true, it would virtually establish my theory, namely that the crime occurred elsewhere and the bodies were brought here. It would also demolish the idea of a lone perp slipping up on a backcountry campers-tent in the middle of the night!
You would have solved the case, and in just the way I would have expected!
[PS To hostile posters: At my age I no longer care what you call me, just so you call me crystalk!]