Yes Muller state park has several loops and will accommodate big rigs. The best site there is 40 and 41 views of pikes peak and big sites with water and electric. Beautiful campground and area. Garden of the Gods, Pikes. peak, cripple creek and more.
Yes! We take our 33ft TT and have no problem. We often see large Class A with Toads in the Park. Some pull thru sites may be a bit tight but a 5th wheel shouldn’t have any trouble fitting in many of the sites in Conifer Ridge loop and Peak view loops which are mainly back-ins.
There are plenty of sites you can fit in at Mueller. To see them, go to https://www.cpwshop.com/camping/mueller-state-park/r/campgroundDetails.page?parkID=50032 and use the form on the left of the page. Select "Show Advanced Options" and put the total length of your truck and fifth wheel, combined. Then you can see the sites where you'll fit. You'll love Mueller!
Most, but not all would be fine. The pull through sites on Revenours Ridge would be your first choice (the ones that go between the main roads). If you do not have to be straight to unhook and hook up your 5th wheel, most of the pull through sites along the main roads would be ok. Try to avoid the back-ins on Peak View and Conifer Ridge.
Yes, there are several long campsites. The pull-thrus are located along the side of the road, like a pull off, which makes it very easy to park. This list shows all of the sites, their lengths, and other details: https://cpw.state.co.us/placestogo/parks/Mueller/Documents/Mueller-SITE-INVENTORY-2017.pdf
Yes, if you select a site with a maximum vehicle length of 40 feet or more (the longer the better, of course). Sites 1 through 4 and 87 through 90 are good choices for larger rigs. The site lengths given on the reservation website are pretty reasonable, in our opinion.