[Which Thrush?]

It's definitely a Wood Thrush.  I always look for the dark spots in front and the reddish brown back. If this was May or June you might have heard it sing.

[Birds of North America]

There is also the National Wildlife Federation's guide Field Guide to Birds of North America which contains many photographs of different species.  It covers extensively the birds throughout all of North America. :)

[Please confirm Swainson's Thrush]

I think the Swainson's Thrush is quite common in the northern part of Michigan-- especially the Upper Peninsula.  I live in the lower peninsula (western part).  This bird will migrate through our area in the spring and fall, but it prefers the wilder areas of my state.  Is it abundant in California?