If you guys can't drive, I suggest look for Japanese tourist groups to go to Yellowstone and Grand Tetons. I think a lot of people also include Mount Rushmore in the same trip. I know there are a number of Chinese based tour company that offer this, there should be Japanese based ones as well, but you'll need to ask around. When booking such trips, try to find one that stays one night in the park, rather than the ones that bus you in to see old faithful than bus you out. I've been there three times, twice we took our own cars and seen a lot, once with my parents, and because that group spent actually two nights in the park, my parents also saw a lot. The tour company that offered that is still around but unfortunately they are Chinese/English based. All tour groups typically pick you up in LA or Salt Lake City...
I think you can do this:
2days in NY
1 day in philly(constitution and liberty bell)
2 days in DC(again try to find Japanese tour group from east coast, due to the fact that your parents don't speak English you may visit more places than these pending the tour package you choose. They may include niagra fall which is definitely worth it. Skip Atlantic city, since Vegas is a much better gambling city to visit.
Fly to sf
2 days in sf(redwood and golden gate)
1 day in Yosemite(prearranged tour groups can be arranged as well)
Fly to la
2 days in la
3 days in Vegas(include Grand Canyon )
Back to la
5 days from la to Salt Lake City, grand Tetons, yellow stone and potentially mount rushmore(again as a tour package)
Fly out from la
You would have a lot more flexibility if your parents can drive and speak English but as it is, your options are limited by these factors.
Sent from my iPhone using
MonsterAquariaNetwork app