Before planning on an extensive stay in Zion during the summer, you might want to look at the temperature history-it is really hot during that period; the only cool part of a visit to Zion then is the wading in the Virgin River in the canyon narrows. Bryce is significantly cooler.
We went to Zion this April and stayed at the campground in Springdale just before entering the park, about 1 mile away. Can't remember the name, but it was a pretty nice place and was $39 per night for full hook-ups including cable tv and some wi-fi. I don't know about 50 amps, but our 30 amp hook-up worked fine. I think it may be called Zion Park Campground. If you stay for seven days, you only have to pay for six. This was one of our very few experiences outside Grand Teton/Colter Bay so we don't really have much to compare to, but we enjoyed it. In April, at least when we were there, the temps got up to 95 one day, 93 one day and dropped to the mid 80s the rest of the week. We day-tripped to Bryce and also Kodachrome State Park in one day. Didn't come in on the tunnel side as we came down the west side of Springdale so you don't always have to use the tunnel.
I would stay at the one in Springdale for Zion (definitely NOT stay at Zion River in Hurricane) and Ruby's in Bryce.
I agree with both recommendations. The RV park in Springdale is easy walking distance to the park HQ where you hop on the park shuttle. True, it's not the greatest park, but it IS on the river (the other bank is in the NP) and you can cool your feet there. With a motorhome and full hookups, who cares what the bathrooms are like? Anyhow, you will spend so much time in the oark you won't want to hang out at the RV park.
Outside Bryce, Ruby's Inn is a great (though pricey) base of operations to see that park. It's easy, and has all the groceries and supplies you'd need.
I'd definitely stay at the RV parks just outside the national parks because you waste less time commuting, and you won't have to pay for all the extra fuel consumption going back and forth.
2008 Rockwood 8272S
2010 Ram 2500 Lone Star CTD 4X4 Megacab
DH+DW 32+ years
Molly the flat-coated retriever
Millie the fawn brindle greyhound
I believe the campground in Springdale that everyone is talking about is Zion Canyon Campground and RV. We stayed there in May and paid $39. It is behind the Best Western on the river. They keep it clean and the hook ups are excellent. Of course it is somewhat tight between units. All sites are pull through but are not real long. You can fit a motorhome and car but not connected. The Wifi is not good but they do have it. It is only a few minutes brom Zion's gate and the free bus picks you up out front. Restaurants are all around and Bryce is about 1.5 hour drive. We stayed there and did both parks. One thing that surprised us about the area was the number of rental units in the campgrounds. Out of the 80 sites probably 45 were rentals which stay no more then two days. The campground is not a great place to set up for a vacation but it is a great choice for Zion. You do have a beautiful view of the walls of what is the beginning of the canyon.
Bob and Ann
One HAPPY Schnauzer - Della
One FRISKY Chihuahua - Lola
2005 37 DB Allegro Bay
GM 8.1L (496 CID)
Onan 7000 Watt
2006 Suzuki Grand Vitara Toad
x2 on the way Zion is run. Out of 10 NP's last year it was my my least fav. The LA fringe has taken it over. Also very little wheel chair access. Except of course to the 5 star resturant where you can eat lunch for 48$ a person. It is really to bad. We won't be going back. The shuttles are a story on there own. I have been to 41 NP's and this was the first time I saw this attitude. It made me sick. I want my kids to enjoy these parks when they have kids. I hope you enjoy it more than I did. Bryce was one of our favs. It is great. Definitly hike down into the hoodo's. Awesome. sorry for the rant. I also do not remember the campgrounds we stayed at. Both were not in either park. They were nothing special, just a place to hook up and sleep in. We spend all day in the parks and other areas. Have a good trip and enjoy the time .