140 years ago, this gravestone of my great great grandfather was fresh and clear. Now, the information about his life can only be read with difficulty. Not long ago my wife and I traveled to Park City Utah, near the birthplace of my father, to combine a week's vacation and a family heritage tour. Thomas Jefferson Thurston pioneered a valley east of Ogden, accumulated a number of worthwhile accomplishments in his 80 years, and passed away in St. George UT in 1885. But outside his family and a few historians, few know of him (yes, he was…