Is it safe to sleep here?

I have never slept here but it's regularly patrolled by the WA State Police and I am not aware of any incidents in the past.

It is not designed for over night. Sleeping in a locked car i would feel safe. Not out in a sleeping bag and no tent sites there.

We have parked in many of the state's rest stops and have felt safe. Remember that the WSP makes passes through these areas during the night. But I wouldn't roll out a sleeping bag on the grass, I'd stay in a vehicle, rv, truck, etc

Yes it is. I truck through and stay here 2 to 3 times a week. I've never seen, heard or found any problems with harrassment or worse, as long as your not going to be my first offender! It's safe, plenty of tables to eat a meal on, and the rest rooms are maintained several times a day. It is patrolled as well. And the truckers are always watching out for any issues, and most will use the CB radio to let others know what's happening, and usually it's a fellow trucker looking for a empty space, never had a bad report. Most drivers also use the accident camera, which is a great relief to have for security as well, because we do haul millions of dollars of commodities and when we park for our rest break, we dont want to have to tackle a thief, vandalism or worse, we want a peaceful rest spot as well...just remember, smile, your on someone's camera. I usually from the restroom point of view, photograph a portion of the parking lot, as a record of some trucks there incase I need video info.