We usually spend the first night inGreat Falls, 5 hours, or if I get out of work early we make it to Butte, 8 hours. A quick
Walmart stop for sandwich supplies, fruit, pop, etc to fill up the cooler. No state tax in Montana ,stock up lots here.
We stopped in Spencer, Idaho to dig for opals. Kinda cool, fairly cheap (I think $5 each). Likely about 50 people live here, don't expect much.The rest area just outide of Idaho Falls is a must stop. It's got a short & long loop to walk around lava holes, forget what they're called so obviously I need to stop there soon. It's a good place to make sandwiches, sit on the grass & relax. I prefer the southbound rest stop to the northbound one.
A couple of times we went to Bear World, 20 minutes east of Idaho Falls, it's a half day adventure, drive thru deer, wolves and such, then another drive thru & see the bears. There's a petting zoo of sorts at the end, playground, gift shop, feed the fish. The best was feeding the bears from the back of a big truck and/or feeding the bear cubs from big baby bottles. Prices ar so/so. My son loved it.
After Idaho Falls, thru Utah there's not a whole lot that we've stopped at. There's an outlet mall at the bottom of Utah in St George that we've roamed around mostly to get a little walking.
If you hit Mesquite, NV on Sun to Thrusday you can get a great rate at the motels. We've stayed for around $25 to 30/night at both the Oasis & Virgin River Motel. I prefer the Oasis for all the pools, kid pool too. The other one has a bowling alley, movie theatre, 2 pools.We sometimes drive down the Strip if we have lots of time. Fill up here - no cheap gas for a long,long time. Also if we have extra time we'll stop in Primm at the outlet mall, sometimes you'll find a deal. Gas is much more costly here.
Start the long drive across the desert. See the world's largest thermoter ( I know it's spelled wrong) you can see and read it from the highway no reason to stop unless you need to pee. We gas up again in Barstow, there's an outlet mall on the west side, I think it's the outside mall type we haven't stopped at check it out.
If you have time and it's not too hot, Calico ghost town is a good place to spend an hour or two. Hint - don't buy chocolate or anything that will melt from the candy store.
I know we've done a few other things but I can't think of them right now.I find gas is usually cheaper at big truck stops, I use Flying J mostly. Lots of times there will be a fast food joint inside the gas station too.
A couple more hours and you're in LA.
We stay at KOA's so can't help you with motels. Lots of the KOA's have camping cabins a bit less than a motel, you'll need your own bedding and usually need to be booked ahead, sometimes just early in the day is fine.
Edited because the lines & paragrahs disappeared.