Maybe this census can help - wasn't available when you posted.
Reno, Washoe, Nevada
Mrs. Charles W Mapes 44, head, widow, b New York
Charles W Mapes Jr. 19, son, b Nevada
Gloria Mapes 14, daughter, b Nevada
Anna E Erickson 63 housekeeper
What was the surname of your grandfather Louis? His date and place of birth? Wife's name? Date and place of marriage?
A clue here:http://www.tahoebonanza.com/article/20010425/OPINION/1042568...