Regarding your "one spare day", I suggest you not assign it to any one location. Inevitably you'll arrive somewhere that you wished you had planned another day, and if an adjustment of the itinerary is possible, you'll have another day. Keep it in the bank to exercise that freedom you've mentioned more than once. If you haven't been able to fit it in you'll have it for Denver, a very nice city.

You are defintely going to want that "extra" day in Arches. I dont remember if you said you are trying to make camping res. you will need them. Also the parking lot at Calf Creek Falls is very small woth only. Few spots. Its also physically small, so your RV might not fit at all. There is nowhere nearby to park except along the very narrow road.

Alcatraz tickets book up far in advance.

Thank you all again!

Yes, I know about Alcatraz tickets. They came recently available for my date.

I am making as much campground reservations in advance as possible, on almost everybody's advice, as it is high season. It's not that easy as a lot of campgrounds are fully booked (I am looking everyday) and the first come, first served are not always that big.
So I would love to keep that extra day in the bank. I'll see where I end up with booking available campgrounds. But as 2 of you suggest to use it in Arches (and not in Zion or Escalante), which is at the end of my trip, makes me happy. I was afraid somebody would state that I need to see the Grand Canyon ...

I've read about the small campground at Calf Creek and it is a first come, first serve. I am planning of staying the 2 nights before at Escalante Petrified Forest State Park (17 & 18 June) to visit the slot canyons and drive early morning to the Calf Creek Falls trail. If no availability at the campground I'll drive further late afternoon (after the hike) in the direction of Capitol Reef NP and look for a campground on the way. Does anyone know if Escalante Petrified Forest would be a good campground? It has showers and everything and is quit cheap.

Thanks again for all your input!!! I can not express my gratitude enough.

Does anyone has an opinion about Needles or Arches?

Where could I use more time for hiking? (it's 3 hours apart from each other), in Arches or Needles?
(The roads in Arches are under construction this summer. I may expect road and trail closures.But can't tell in advance which ones. It can also cause more traffic jams in the park).

There's a campground at Goblin Valley State Park.
https://utahstateparks.reserveameric...&parkId=344291
There is also a nice campground along the river in the town of Green River.