I live in Salem, Oregon and retired two years ago. Like a lot of RV'ers we are find out that it is a must to do your homework before heading out. I do not like staying over night at Wal-Mart type parking lots or some named RV Park that is one step above a home-less camp. It is getting were you need to start planning and making reservations 6 to 9 months in advanceto insure that you have a spot to stay. For example, the Oregon coast State Parks you need to book 6 months or more in advance or you will probably not get a RV site all summer long into October.
I try to make RV trips in mid September. Good weather and hopefully trying to miss the crowds.
We have been planing a trip to Utah, New Mexico, Arizona in May for a month to adviod the heat and crowds. Started planning in December of 2019 for a trip in May of 2020. Remember, every Man, Women,dog and child likes to go during the summer months because that is the only time they can take off for vacation. I hear Yellow Stone traffic in the summer months is like go through Portland,Oregon or LA during rush hour.
