Complex sentence: Will Grant Bagley (born 1950) is a Utah historian, specializing in early pioneer history of Utah and of the western United States, who has written about overland emigration, frontier violence, railroads, mining, and the Mormons.
Split into simpler sentences: Will Grant Bagley (born 1950) is a Utah historian, specializing in early pioneer history of Utah and of the western United States. Will Bagley is a Western historian who has written about overland emigration, frontier violence, railroads, mining, and the Mormons.