Hi fellow travellers :)

We (4 adults) are planning a 4 week trip in August 2016.

Main attraction is Yellowstone, so the plan so far is:

SF to LA via Highway 1. 2 days, with stop at Pismo Beach
LA. 2 days
LA to Las Vegas. 1 day
Las Vegas. 2-3 days
Las Vegas to Salt Lake City. 1 day.
Salt Lake City. 1 day
Salt Lake City to Yellowstone. 1 day.
Yellowstone. 3-4 days. Maybe more ?

So about half the vacation spent, and we need to get back too.

Now, I'm stuck at Yellowstone, and could really need an advise what to see/go next ?
Something we would like to see too:

Grand Canyon
Mount Rushmore (probably not doable)
Anything else on the way, time permits

Now, just looking at the map, I just got an idea:
Maybe, if I can get the other in my group to confirm, we could start at SF, and end in Seattle or vice versa ?
So also hints on what to see in Seattle and between Seattle and Yellowstone.


Thanks

Boost