I have another question to ask the forum:
We are potentially planning a trip to San Francisco and surrounding area for October 4 - 14. We plan on spending 2 nights in the Sonoma area and 3 nights in San Francisco. Our first thought was to travel up the coast to Mendocino and Klamath areas for the remaining days. But, now we're second guessing ourselves. Should we go to Yosemite instead during this time? We live on the East Coast, and won't be able to get out to California again probably for some time. Also, I'm a teacher and am generally in school during the "off" season. However, I will be on maternity leave this fall and am trying to take advantage of that very precious time off.
Thank you so much for your help!

Are you planning on bringing a baby on this trip? If you will be 8-9 mo. pregnant your Dr. will not let you travel that far from home.
That said, Yosemite is a beautiful place to visit in October and even November.
If you go as far up the coast as Redwood NP (Klamath) you could make the trip over US 199 and see the Oregon Caves National Monument and then east from Grants Pass Oregon to Crater Lake NP. It is an easy trip from Crater Lake using I-5 back to San Francisco.

Yosemite is one of the most beautiful spots on this planet. I would choose it over any part of the northern California coast, without one micro-second of hesitation.

no, we're not planning a trip with the baby. The baby will be 3 months old and staying with her Grammie while we have a getaway vacation before I go back to work. We're taking advantage of that time alone to have a spa/mud treatment in Conastoga, sip some wine in Sonoma, and enjoy some beautiful scenery!

I really like the coast that time of year, but either way would make a great trip. You'll have wonderful weather in both locations.

The one drawback to visiting Yosemite in the fall is that, without any rain or snow for months, the waterfalls won't be flowing. But even without waterfalls, Yosemite should still spectacular. On the plus side, it won't be anywhere near as crowded as it is during the summer.

Good for you katahdin! I think for the type of trip you are taking, I'd go to the north coast. I like Yosemite a lot too, of course, but I find that rugged north coast to be quite romantic.

BTW - I think you mean Calistoga for the spa treatment rather than Conastoga. I don't intend to split hairs, just wanted to make sure you had the name right so that if you did a web search for something, the right things came up.

lol, yes, I did mean Calistoga. That was "preggo brain" kicking in at its best! What a silly mistake! Oops!
We plan on staying at Golden Haven Hot Springs while in Calistoga and getting our spa treatments while there. I'm very excited to get away!
Thank you for the replies so far! I welcome more opinions as well!

Haha - "prego brain" I just wanted to make sure you didn't end up with links to sites about wagon trains heading out across the prairie.

"I did mean Calistoga. That was "preggo brain" kicking in at its best!"

Sam Brannan made a similar slip of tongue (that's how Calistoga got its name) but it wasn't due to "preggo brain".

It's a tough call, but if you've never been to Yosemite, it would receive my vote.

If time permits, you could include a drive down Highway 49 through Gold Rush country: http://www.historichwy49.com/

After visiting Yosemite, you could drive over to Cambria on the coast via Paso Robles and beautiful Highway 46, and return to San Francisco on Highway 1 via Big Sur, Carmel, Monterey, Santa Cruz, and Half Moon Bay.

HTTY

I think it's a tough choice. Both locations are beautiful. Perhaps it will depend on your interest in hiking. Redwood National Forest is a great experience if you like to hike or walk. You just cannot really experience this park properly unless you get out of your car. In Yosemite, the views are awesome from the car, bus or shuttle, and you can take extremely short walks if you like. Yosemite Valley is fairly compact and you can enjoy major sights from the parking lot. The lodging and restaurants are primarily in the valley. In the Redwoods, services are spread out and fairly far apart. If I were you, I'd google some images of both parks and just determine which area calls to me the most. They are both wonderful. (And each is about a 5 hr drive from Napa).
(I do have a recent trip report of the Redwoods with some photos, if that helps. Click on my name and scroll to Trip Reports).
You can't go wrong with either decision.

I recommend you go to Yosemite. In my opinion, it is the most beautiful place in the entire world. If you do not go there on this trip, you must go there at some point. As Shanti noted, it is at it's best when the waterfalls are flowing.

Whatever you decide, I hope you have a great trip.

Thank you all for your responses. It is a very tough call, because I really want to see both! Thankfully, I have some time to think this through, although I understand lodging books fairly quickly, especially for the summer months. However, I know we can't afford to stay inside Yosemite; we'll have to stay in a surrounding community and drive in everyday. I'm not a huge city-goer, so we may cut down the amount of time in San Francisco, and try to see both Yosemite and the northern coast.
Again, thank you all.