In Carey McWilliams’s California: The Great Exception, there is a section about a startling type of woman living in the mining towns born in the Gold Rush. These women were neither wives nor mothers. Not maids, not cooks. A popular barroom ballad from the decade: The miners came in forty-nine, The whores in fifty-one; When they got together, They produced the native son. Melinda Clarke, the actress who portrayed Julie Cooper on the popular teen…