In 2010, on the way to Yellowstone, we did an overnight by Springville at
Cherry Creek Nat'l Forest CG ....others near it as well.
Never been to it
http://freecampsites.net/parowan-gap-petroglyphs-utah/.
Walmart Supercenter -
1330 So Providence Center Dr, Cedar City
435-586-0172
North of Nephi
Walmart Supercenter -
1052 South Turf Farm Road, Payson
801-465-8246
South of Cedar City
Walmart -
180 North 3400 West, Hurricane
435-635-6945
Walmart Supercenter -
625 W Telegraph St, Washington
435-628-2802
No overnighting at Wamart in St George it seems.
Little Black Mountain Petroglyphs - In Arizizona, below St George Virgin River - AZ strip, ArizonaWalmart Supercenter - Someone posted:
Jun 2012: I called ahead to get permission, and asked again, in person, after I arrived. Each time I was told its okay to park in a remote area of the lot. Apr 2012: Did not ask but signs are posted. Dec 2010: asked and allowed to park overnight by the manager. It has been no overnight parking in the past so be sure to ask.
1120 West Pioneer Blvd, Mesquite NV
702-346-0208
CasaBlanca Casino - Mesquite, Nevada Little America, WY or
White Mt Rd Green River/Rock Springs, WY Wind River Casino - Riverton, WyomingWe've gone by Thermopolis, WY twice to do a soak in the hot spring water at the State Bath House. Very neat.

We overnighted in the Wind River Canyon in Aug '09 & at one of the Boysen State Park campgrounds by the lake some years ago.
Hot SpringsCody Walmart was our neatest Walmart Overnight Site yet:

Cody is a neat place. In Cody, try to see the Buffalo Bill Historical Center with Five Museums Under One Roof.
http://www.bbhc.org/The Cody Chamber of Commerce has a nice Visitor Center (full of information) & with a really nice art gallery.
http://codychamber.org/visitorcenter.htmlNever been to it, but they have a Cody Night Rodeo with rodeo performances every night June 1st through August 31st. Gates open at 7:00 p.m. with rodeo action starting at 8:00 p.m.
http://www.codynightrodeo.com/ And a Cody Stampede Rodeo July 1 to 4,
http://www.codystampederodeo.com/ Many Years ago, we spent an overnight at
Homesteader Park - Powell, but seems no longer allowed.
A little to far East, Just in case I'll add:
Overnighting Sites & Sights in the
Douglas & Wheatland Area. Includes Guernsey & Fort Laramie Area.
Guernsey State Park -------
Fort Laramie National Historic Site ------
Oregon Trail Ruts and
Register Cliff