In most pulloffs unless there is a NO OVERNIGHT PARKING feel free to take a nap. If your there June 21 there is no night. As someone already mentioned there is a pulloff north of cantwell where there were several rvs parked for the three days we were there. One was a 5thwheel unhooked and a couple MHs with toads unattached. There are several SP along the highways with cheap overnight parking. Some like most rv parks in AK are not much more than parking lots with pit toilets. Your not there for the rv park your there for the majestery of the scenery and with luck the wildlife. The fishing is great too.
It would have to be a real slow night for SP to bother you in any pulloff those guys cover a lot of territory sometimes for RVers that figured they could drive another 100 mile beause the sun was up.