The problem with sleeping on the ground is that it is a heat sink and will pull heat right out of your body. One of those 1/2" or so thick closed cell foam pads will insulate you from that problem but you WILL feel every rock underneath it. Those standard blow-up ones with 2" or 3" chambers will solve the sleeping on rocks problem but they do nothing to insulate you from the ground "heat-sink" problem. The REAL ANSWER is to get one of the self-inflating pads like the Thermarest ones. I bought one in the 90's and it always goes with me, whenever I pack a sleeping bag. They are not cheap but that have polyurethane foam padding inside that shields you from the heat-sink effect of the ground and they also provide cushioning so you don't have problems with small rocks.
These self-inflating pads roll up very thin and they are very light. When you get to the campsite, you open the valve and let it reinflate. It might take a couple of minutes, but then 1 or 2 puffs into the valve before you close it and it will be perfect. They typically inflate to about 1¾ to 2" thick and are SOOOOO comfy to sleep on. Additionally, I got one of those backpacker chair adapters that consists of some nylon and a couple of ribs - also rolls up very small. You put your inflated Thermarest pad into the top and bottom of it. That stretches out the side panels and because you are sitting on a padded bottom the nylon side panels stabilize the backrest, making them surprisingly comfortable to sit in.
I bought it because my brother said I really needed one. He taught an outdoor school at Stanford University along with a small corps of instructors that would rotate leadership year to year. He is an avid back packer and rock climber, mountain climber, and really knows his stuff. Helped me pick out some good hiking boots that I eventually wore out (still miss those!) and set me up with one of the school's backpacks for our 6-mile hike into the Desolation Wilderness near Lake Tahoe. Destination was a high lake (Clyde Lake) where I had a chance to catch some Golden Trout. Elevation of the lake itself was 8,100-feet, just a few hundred feet from the pinnacle, which we did have to hike over. Most other spots for Golden Trout in the Sierra are at elevations above 9,000-feet.
Air gets pretty thing up there and you get tired quickly so you have to adjust your activity accordingly. This was just an overnight hike for us and the following morning I did catch a 14" golden trout, which I admired for a couple of seconds and then released. You can catch much larger trout at lower elevations, but golden trout survive the high country better than most trout. Problem with that high country is the fish have a very short growing season because they get snowed on and iced over for much of the year. A 14" Golden Trout can easily be a 6-year old fish, whereas a 14" fish from down around 3,000-ft. or so would usually be a 3-year old.
Was amazingly clear and deep water with house-sized giant boulders in it. Bad news is that a few years later, CA Fish & Game decided that Clyde Lake had the perfect habit for some frog species (yellow-legged frog perhaps?). So they poisoned the lake to wipe out all the fish (fish could eat these small frogs) and planted these endangered species of frogs into the lake. So it really is frog-water now. Too bad because it was spectacular scenery bounded on one side with about a 200 to 300-ft. tall cliff that looked like God had made that cliff by taken a big ice-cream scoop to the granite hillside that bordered the lake.
Anyhow, was very comfortable with that set-up and has been ever since. I used it for a lot of reenactments inside my tent, with the Thermarest Pad hiding underneath my 2 wool blankets. I could leave the door flap half open and folks would never know I had it. They are great!
Looks like they run from $119 to $155 now days from REI. Mine was the original Orange color from back in the day. AND the really good news is that I found a much newer one in a thrift store about 10-years ago and bought it for $10. So now I have two. You'd be amazed at what shows up in thrift shops, and nobody recognized it for what it was.
Here's a link to the
Thermarest Pads on REI's web site. Just about any backpacking store will have these or similar self-inflating pads. typically the differences between regular, large, and X-Large are wider widths. You bean poles out there can get the regular width. Mine are both the large width.
And here's a video about the Thermarest pad