Lost Union Payroll

On Dec 30, 1862 during the Civil War, Union Colonel C L Dunham of the 39th Iowa Regiment was ordered to seek out and destroy the CSA 7th Tennessee Calvary Brigade of General Nathan Bedford Forrest. Forrest was known to never give or expect quarter, so before the engagement, Dunham had two Lieutenants and a Sargent (possibly Quartermaster Adams) bury the payroll strongbox of $15,000 gold US coins 200 feet due east of one of the five springs located at Dollar Hill, where the Union had pitched camp.
The next morning, Dec 31, 1862, Dunham's regiment met Forrest's at Parker Crossroads, and heavy casualties were inflicted on the Union. As Dunham ordered retreat, a rain storm flooded the area.
Dunham and his remaining men returned to Dollar Hill to retrieve the strongbox, only to find the area was "a sea of mud and standing water", and quickly departed to avoid CSA patrols.
This is one of the few lost gold stories of the Civil War to be real. Allen Chambliss, a teenager from Huntington,Tn, who Dunham hired as a scout, witnessed the burying of the stongbox and the battle, and lived to tell this tale. It was also confirmed in Colonel Dunham's report of this encounter with CSA General Forrest.
Here are some interesting facts:
Colonel Dunham reported 23 killed, 139 wounded, and 58 missing. One Lieutenant acting as his aide and Quartermaster Adams were captured leaving only two possibly three who knew where the strongbox was buried. They arrived at Clarksburg after dark on the 30th, taking breakfast and departing for Parker Crossroads at daybreak.
Poplar Springs located along Dollar Hill Road would be a good place to begin.
May all of your trails be smooth and your treasure sites many. 
Best Wishes and Good Hunting