The timeline of Walz’s service and the deployment of his unit, the 1st Battalion, 125th Field Artillery Regiment, is relatively clear, through public records, news accounts and press releases at the time:
The 125th Field Artillery Regiment received initial call-up orders in July 2005 and deployed for training in Mississippi that fall as part of the 34th Infantry Divisions’ 1st Brigade Combat Team.
The 125th deployed to Iraq in March 2006, 10 months after Walz had separated from the unit.
The timeline laid out in official documents does not cover several factors common to nearly any military unit. Walz, as a senior member of the unit’s leadership, likely knew a deployment was in the unit’s future before the July 2005 activation order. Extended deployments and National Guard activations are often planned across the Army a year or more before formal orders are issued. But the May 2005 date on which Walz’s retirement became official was likely many months after he had ‘dropped his papers’ to inform his chain of command he intended to retire, beginning the process.