Best size TT for exploring the National Parks?

Get a small 10x10 tent (or a screened enclosure for your awning) that the kids can stand upright in and a couple of light weight cots. Then you can really cut down on the crowding when the weather is decent.

You have received some good advice so far. I will pile on to the low to mid 20's end to end for the type of camping you want to do. We like to do the same kind of camping. My 180ck is 22'4" hitch to bumper, and there have been times I was really glad it wasn't longer. National parks, out here especially, have A FEW sites to accomodate larger rigs, but they are limited and sell out very quickly. Shorter gives you more options. Sometimes I wish I had a TC, like we did when I was growing up, I would never have to worry about site length.

Our 180ck is one of the most common small trailer floor plans, and works very well for my family of 5 (often 6 with DW's aunt) It has a single over double in the back next to the bathroom. A 72" length dinette with drop down table, the kind attached to a hinge on the wall and a single fold up leg, it literally converts in seconds. A jacknife sofa along the front wall that also converts in seconds. There is plenty of storage as well. It is a very efficent use of space. We don't have a slide and that is ok by me. Most manufactures make a version of this floorplan, calling it a 18 or 19 or maybe 20 something model.

In order to keep a shorter length for the kind of camping you want to do, you will generally have to have a corner bed of some kind. Models with walk arounds in this size are usually for 2 people and will not function for a family. My inlaws have a trailer like this, it is perfect for the 2 of them.

For us, we keep the double made up like a bed, and the 3 kids have sleeping bags and pillows. In transit, all our bags and suitcases are on the single over bunk, I have a toddler bed rail I installed to keep everything up there. The sleeping bags, pillows and blankes go under the couch. At bedtime I drop the couch and dinette, pull out the sleeping bags, kids clothing bags go under the table and ours go in the bath tub in the bathroom. Takes about 5 minutes to change from awake to sleep configuration.

Here are a couple other interesting floorplans though they are in the mid 20's
Rockwood mini lite 2306
Jay Feather 23k not made anymore but a very interesting floorplan, actually has that walk around bed plus bunks in a 27ft hitch to bumper trailer

If I was looking today, for our camping style and family of 5, the Lance 2185 would be near the top of the list

My 26' is tight fit at times. Less is more.
Get a slide for more interior space.

I would go with something in the low 20's for length. Slideout is fine but the extra wide models are not. Anything bigger and you won't be able to fit in most of the campgrounds (might get lucky and find the 1 or 2 spots open in each campground that could kinda-sorta fit a 30' trailer, but usually not). A hybrid type (fold out bunks) may be a good idea for extra floor space (and they're light too), although some places like Glacier Park require hard sided trailers where there are bears. Make sure it's set up well for dry camping since you'll hardly ever have hookups -- LED lights, extra battery/generator/solar, way to take on and empty water tanks...

However, DO IT! The NP and Forest Service campgrounds are all beautiful and relaxing. So many people seem to HAVE to have hookups and space for their 35 foot toy hauler or class A these days, and they're missing out. Get off the beaten path.

If you post the specs on your TV many on the forum can give you a good idea of what you can tow. The weak point with ½ tons is payload; you’ll run out of that before you reach any of the other ratings. You’ll find you will have to choose between features you want; everything is a compromise with RV’s.

When you get near the 30’ area you’ll have lots of space and amenities and comfort. Sort of like a mobile motel room. The tradeoff is you’ll have limitations on where you can go. Some scenic roads and less developed campgrounds will be off limits. You choice of campsites will be reduced too, and you’ll likely have to make reservations to ensure you can get a site.I don’t think many people buy a big unit to dry camp either; they’ll want hookups for the most part. Most campgrounds don’t have hookups, e.g., Yellowstone and the Tetons only have one cg each with hookups so many people stay in commercial cg’s outside the park.

Small and light gives you far more flexibility as far as finding camp sites and they’re easier to tow, especially if you do much mountain driving. The tradeoff there of course is the reduced space and amenities. You’re the only one who can balance off the pros and cons and settle on a unit that you’re happy with.

I view 30’ plus units as one end of the bell curve. I’m on the other end. My goal is to get well back into national forests and I have a 16’ TT. I routinely can get a spot in the parks without reservations even in prime season and it’s a piece of cake to pull even in the mountains. But I don’t have the comfort and features of a big rig, which is OK with me, in my view I’m camping and comfort isn’t my top priority.

If you’re looking at 30’ units you wouldn’t be happy with mine. If I wanted as much space as possible and still wanted a lot of flexibility to find sites I’d look at 25’ and less units. You would have more opportunities for campsites and less restriction on where you could go.

This being your first TT I’d suggest you seriously consider a nice, late model used one. Most people find, after they’ve used it for awhile, their first choice isn’t what they really want and they replace it with something more suitable. Considering the rapid depreciation of RV’s, that can get expensive if you’re buying new. Good luck on your decision.

The OP is looking for a mid 20' bunkhouse!

WoodGlue

In spite of the usual "bigger is better", I would stick with the mid-20's length. Both because of your half-ton truck and for getting into more campsites easier. It won't be easy with a family of 4 but I still wouldn't overdue size.

Ascend makes a bunk house model, 23 ft IIRC.
bumpy

yes

In the Jayco 197, are you able to access the bathroom with the slide in?

WoodGlue