I wouldn't personally drive all that way to see Galen Rowell's prints - or those of the others I've seen in that gallery. But if you can time it right and combine aspects like Death Valley, Alabama Hills, Mono Lake, June Lake loop, Convict Lake, maybe Bodie etc you could put together a nice short or medium length trip with Bishop and the gallery thrown in with no trouble. You might think about visiting quirky little places like Keeler and Randsburg en route. The last time I was in Bishop- in late April 06- the entire area up around Lake Sabrina was the centre of an enorous project for water or electricity or both and it didn't look to me like that was going to look nice again anytime soon. Otherwise the immediate vicinity of Bishop, and the town itself are not particularly spectacular IMO. Still, taken as a total the eastern Sierra can be particularly nice in late spring with snowy mountains as a backdrop ( and the possibility of more snow than you'd ideally want on some roads) or in autumn.
Unlike most of the people responding here, I'm not a Rowell fan; and neither do i think a lot of the other landscape photographers I've seen displayed there whose work I think to be oversaturated and gaudy. I'd drive a few hours to photograph in the Alabama Hills though!