You are correct, the counties parcels show Flying M Drive as the streetname. That isn't unusual, they just assume a driveway access, often accompanied by a shared private service road. 

I'm very familiar with this concept. I've added thousands of addresses in Washington State. 

Now if the street is signed, then that is a whole different story. I have found errors in county addresses. One set in King County took me 3 years before the county fixed it.