The cost of living is definitely infinitely higher than living in the midwest but you certainly can find fields and forests (and actual mountains!) in the SF area. For example, the minute you cross the Golden Gate bridge, you are in Marin County, a county with a rich agricultural history, amazing natural places like Muir Woods (the setting for the ape's home in the latest Planet of the Apes), and 85.5% of it's land protected from development forever. Here's a photo from the Headlands (
http://www.robertcampbellphotography.com/Images/Marin/Marin-...), you can see SF just in the background, it's about 10 miles away from Downtown to the place in the photo. If you live in Marin, you can also choose to take the Ferry which drops you off in Downtown SF as well.
If you go South-West of SF, you will hit Pacifica and Half Moon Bay which are quaint coastal towns that will make you forget that you're only 20 miles away from San Francisco.
Go East, past the hills of Berkeley and you hit more rural spread out developments near Orinda, Diablo, etc.
I'm glad you found balance with the things that are important to you which is what really matters. Me personally, I'm drawn to the coast and the great expanse of the Pacific Ocean. The SF area has it's fair share of urban problems, but then you also have amazing restaurants, a close-to-world-class arts scene, some of the best schools and hospitals in the country, the most impactful technology companies in the world, and the fair share of folks who have come West looking to make their mark on the world in Gold Rush 2.0.
P.S. I've spent a fair share of time in Detroit/Michigan and the area and as much as I love being able to buy a city block there, I can't live in a place that calls soy sauce on rice "Fried Rice".