Snowflake, set amid the open sky and vast emptiness of the high desert, is more than just the senator's hometown. Its whimsical name derives from those of two Mormon settlers, Erastus Snow and William J. Flake, the senator's great-great-grandfather.Today, hundreds of Flake descendants, including the senator's mother, live in the town of about 5,500, which is dotted with unofficial shrines to its early settlers and Mormon heritage. The James M. Flake pioneer home is catty-corner from the Eugene Flake heritage barn; a block away, at the pioneer museum, a Flake cousin last week was offering free tour