Family Vacation Out West

3-4 weeks is not long enough to come across country and back a different route.
I would stay off the Interstate highways and use federal US highways and major state routes.
Suggest not making reservations too far in advance. Normally you can find campsites with no reservations except at major parks (not RV) and holiday weekends.
Use a map to start with. Mark the states that you think you want to visit. Go to each states tourism site and order their vacation planner and a state map.
Start marking them up, then have each person mark them up as to what looks interesting to them.

My one piece of advice to figure what you might want to see in each state is to go to Google and type in " what is there to see in xxx". We have found soooo much info that way. I wait till 1-3 days ahead and make reservations, however we don't travel in busy season (summer). We stayed in Kanab Utah and went to Grand Canyon, north rim, Brice Canyon, and Zion. Note: don't try to see them on the weekends. READ, READ, RESEARCH, RESEARCH. You've got a good start by being on this forum.

Regarding redwoods, I would recommend 2 locations. One is the "Avenue of the giants". A web search will give you all you need to know. I would also recommend Jedediah Smith State Park near the coast and Cal/Ore state line. Unbelievable grove of giant Redwoods located across the river from the camping areas.

You are in a BIG coach. In the west that will limit both your accommodations & what you can see. Are you towing a dinghy? Planning to rent a car? Daily sight seeing in that big coach will not be the best way to see things. Your enthusiasm is awesome, but as many inexperienced RV'ers do, you're trying to do too much. In way too short of a time. A trip to see the redwoods is really 2 trips. Are you talking those in the Sierra around Sequia & Yosemite or those on the Northern California Coast? I'd suggest you consider starting with just the South Rim of the Grand Canyon, things nearby & on the way there. Start looking now for parks that will take a 45'er. You might not need to make reservations just yet, but you absolutely do not want to try to take that big of a coach into the major tourist draws out west without reservations. Weekends will be especially problematic. (To find good parks, start with the trip planning section of this website. Then narrow it down using the park review websites like Campendium, TripAdvisor, Yelp, & rvparkreviews. I also like the rvparky app.)

You could use the Good Sam Trip Planner.
Trip planner
Another good reference for locating Campgrounds is the Good Sam Campground Guide. Camping guide

As others have suggested----3 to 4 weeks is a very limited period of time for the trip you are planning. Generally speaking:
1. travel time-- most(not all) RVers only travel about 300 to 400 miles per day and/or 5 hrs. per day. When you go beyond these times or miles you will gradually feel some negative wear and tear on your body and general moods. 4 people in 1 RV can become tense and stressful on relationships.
2. Reservations----Look at your travel agenda for the trip and try to make as many reservations in advance as you can. Nothing worse than pulling into a strange town and begin a search for a RV park at the end of a long day driving. Reservations are not ball and chains, you always cancel or reschedule a reservation.
3. Strongly suggest a "Emergency Road Side Service" plan in the event of break downs i.e. blow out a tire, dead battery, RV won't start etc etc.
4. Tires--- if your tires are 4 yrs. or more old---throw them away and put some LT tires with "E", "G" or heavier tires on. Your tires may look like they have good thread left but after 4 to 5 yrs. you pushing your luck!!!!
5. Make a list of the most desired places to see/visit for each person and then rank them in terms of priority for each person.
6. Check the weather conditions each day before you start. iPhone, Lap top, weather radio, CB radio for weather conditions and for road information/conditions from 18 wheelers i.e. accidents ahead of you, possible alternate routes if road ahead is blocked.
enjoy your trip:)

Also, you can use the Walmart parking lots and many Elks have camp spots, as does the VFW, American Legion.
Buy the Goodall's camp ground directory, use the mobile phone to get reservations and the such.
And with that big coach you won't need hook ups every night.

Yes the 3-4 weeks is too short.

Don't know if you have ever done the RV thing before or not... It is more than just getting into the coach and heading West...

You really should do a few short trips at first so you can learn how things works... Sort of doing a few baby steps at first...

You have one hugh coach and if anythings happens I guess you all are thinking we can just call the auto club and all will be just fine...

You got a whole bunch of systems to learn about your coach... Shore Power, Converter/Charger, Batteries, PowerInverter, etc...

Good luck with that haha...

Just some of my thoughts...

Roy Ken

As others have said, the first step is to decide where you want to go and get the maps out and see what things are along the way.

We we travel we drive a lot in a short period of time too, but I like to drive during the evening when the others are sleeping. It works well for us. But it does take a toll after a few days. When you only have a certain amount of vacation you have to make the most of it.

On of my favorite tools for finding good campgrounds is RV Park Reviews. Once you find a campground that you want to stay, look it up on here and see what others have to say about it.

But to help with other incidentals I have some follow-up questions:

What year RV did your dad buy? Has he driven something of this length before? Will you set it up to tow another vehicle behind it for sightseeing? Have you guys done any camping or RVing in the past? (and yes, they are completely different animals) When are thinking about going?

Doug

Driving straight thru to the west coast you are looking at about 3,000 miles one way. Assuming 500 miles per day (a long day on the road by the way) that is 6 days travel each way, or 12 days total. Nearly half your allotted time will be on the road, and that does not count all the side trips to see the various attractions. 3 weeks would leave you very little time for sight seeing or staying at one place more than a day or two. 4 weeks would be better but still on the move a lot. Not trying to discourage it, just make sure you realize what you are in for.

There is a lot to see across NM, AZ, CA, OR, UT, NV, WY, ID, MT, and CO. Just have to look at all the options and make decisions on everyone's priorities. You can't see it all.