looking for great-grandfather's family Simon Sierra in California. In 1930's part of the family moved to Silvis, Illinois. If your family is from Leon GTO,Mexico that is where my great-grandfather is from. My great-grandmothers maiden name is Terronez and my great-great-grandfather's name was Hercules. If you have any information or would like information please contact me at my e-mail address or my fathers address at email@example.com.