These toy or souvenir plates were made by John Thomson (& Sons) at the Annfield Pottery (1826-1883) in Glasgow. They are part of a series of plates that are mainly unrelated. "Indian Chiefs," "Highland Dance," and "Royal Exchange" (Glasgow) are a few of the other patterns.
Panning for gold in California was the rage between 1849-1864. Among the many who arrived in California in the 1850s was my husband's great great great (he doesn't remember how many greats) grandfather. Unfortunately, he didn't find any gold. Luckily, the "gold" in California today is real estate.