For Spring 2016, University of Oklahoma Press is staying out west with The Civil War Years in Utah: The Kingdom of God and the Territory That Did Not Fight by John G. Maxwell and Jesus de al Teja's Lone Star Unionism, Dissent, and Resistance: Other Sides of Civil War Texas. Texas Unionism and the state's anti-Confederate resistance in its many forms have received a good deal of attention lately but the most recent treatment of 1861-65 Utah remains (I think) 1981's The Saints and Union: Utah Territory during the Civil War by E.B. Long.
Also, the next Civil War related title from UOP's Campaigns and Commanders series will be Bruce Venter's Kill Jeff Davis: The Union Raid on Richmond, 1864. I believe the subject (at least the Dahlgren part of it) was last explored in book format in Eric Wittenberg's Dahlgren bio Like a Meteor Blazing Brightly: The Short but Controversial Life of Colonel Ulric Dahlgren (2009) and before that Duane Schulz's The Dahlgren Affair: Terror and Conspiracy in the Civil War (1998).