My husband and I will be taking a trip to San Francisco (from Philadelphia) in August. We would like to do a one day tour of Yosemite; we have found a few that leave from San Francisco. Has anybody done this? Which tour is the best?

I'm not familiar with any tours, but you'll need more than one day; yosemite is about 4 hours from san francisco. You'll also need more than a day to even remotely 'scratch' the surface of yosemite, it's one of our grandest nat'l parks.

This will top your post however, and someone else will likely know something about tours.

Yosemite is a treasure and certainly worth at least a few days.

A couple of years ago we celebrated my husbands 50th B-Day in Yosemite at the Ahwahnee Lodge. I was busy orangizing all the surprise guests that flew in from all over the US...ny DSIL saw how frazzeled I was and how little time I had too myself and booked a tram tour one afternoon from the Lodge. We had the best time just the 2 of us...and we saw the valley from the tram with a tour guide..if we had done it on our own we would have missed alot.
The Ahwahnne Concierge could help with the info..she sure worked miracles for me..and got a big tip.

Yes, once you DO arrive in Yosemite from San Francisco, you can take several tours. The Valley Floor tour from Toulome / Yosemite Lodge is excellent. Take the latest tour of the day, at sunset in the summer, for the best chance of seeing wildlife, and also not having to squint to see the climbers on El Capitan. (And you'll also need binocs to see them.)

The Mariposa Grove tour is also excellent, stopping several times to allow you to wander around. Sit on the left side of the tram for the best view, although the tram retraces its route on the return trip, but without the audio guide.

There is an extra fee for both tours, but both well worth it. But again, i don't see how it's at all possible to do as a day trip from san francsisco.

Yes - you DO need more than one day. But that simply isn't practical in your case. Finding accomodations in Yosemite Valley (the only place that makes sense for a 1 nighter) in August is nearly impossible

So go ahead and book one of the day trips out of SF. There are two companies that I am aware of and both are about the same itinerary wise.

Is it a perfect choice - no. But it is certainly doable and better to see the Valley by tour than not at all.