Unfortunately, I've not found anything for you, but I haven't yet given up looking.
Did I find the correct family:
James and Margaret Smith had several children, the first one was born in California c1863, the next child was born in Canada c1865.
According to Canadian census returns, James was a carpenter.
Have you tried to track Margaret's siblings, to see if any of them were in California c1862? While I am not American and don't know a lot about California history, I would think that perhaps Margaret would not have been living in that part of California during the mid-1800s on her own.
Perhaps she came out to California with family or a friend? Do you know if she had an occupation prior to her marriage?
I visited Volcano many years ago (I am very interested in the California Gold Rush and remember the town's unusual name).
Volcano is quite a distance from current major towns - I wonder why she would have been in that part of California - maybe she was travelling with Mr. Smith?
If I remember correctly, the current "Highway 49" uses the same route that miners used during the mid-1800s. Volcano isn't too far from Highway 49; perhaps Margaret ended up in the area after travelling from a town or city located near Highway 49.
I cannot view the image at the moment, but I believe J. James was officiating the marriage? According to online information, there was a J. James who was a pastor for a methodist church in Amador County during the 1860s. I believe he moved around, as he was needed. J. James was in Volcano in 1861:
http://cdnc.ucr.edu/cgi-bin/cdnc?a=d&d=SDU18610917.2.16#Perhaps James Smith was Methodist?
I started to look for Smith men in Amador County, but did not finish; perhaps James was not the only Smith family member in that area (which may give us clues to other family members).
I will resume looking later today.