In the spirit of Halloween, we look back at an age-old mystery that has baffled history buffs for years. Long before Sioux Falls became a city, two early pioneers were ambushed and killed on the edge of town.  More than a century later, there is still some debate on what happened to the two bodies.

Standing high on a hill overlooking the city of Sioux Falls, this granite memorial symbolizes the struggles the early pioneers endured while settling a small piece of land along the Big Sioux River.

"This was a brand new territory. They're weren't many people and you were pretty much on your own," Sioux Falls Historical Society member Bruce Blake said.

Alongside the Pioneer Memorial is another historical marker that describes an event known as the Amidon Affair.

"It's the best early story we have.  It's the only major Indian conflict story of settlers coming in and taking the land away from the Indians," Blake said.

About 50 people settled on a small piece of land near the falls of the Big Sioux. Among them, Judge Joseph Amidon and his 18-year-old son, William. William was hunting crows in a nearby cornfield when he discovered just how dangerous the wide open plains were at the time.

"He stumbled upon a party of Santee Sioux who were hiding not far from where we are standing," Blake said.

The warriors had been ordered to clear all settlers from the Big Sioux River valley.

"Not to alarm his father, they shot him with a number of arrows.  They took his shotgun or rifle and when his father came looking for him, they shot and killed him with his own gun," Blake said.

The next day, a small group of soldiers under orders to protect this small settlement, discovered the bodies. The small village was evacuated right before it was pillaged and burned.

"If this had not happened, if Willy wouldn't have gone to look for crows in the cornfield, probably after dark or at dawn the next day, there could have been a massacre and many of those settlers may have be killed," Blake said.

Blake says the pioneers eventually returned and along with many others helped Sioux Falls become a city in 1877. To this day, no one really knows where the Amidons are buried. Many early reports say the judge and his son were buried near the spot where they were killed.

"In fact, there was a large mound about 30 feet in length and waist high," Blake said. 

Nearly 100 years after the attack, the historical society called on archeologist Adrian Hannus to search the site.

"When we did the excavations around that, we found that it was just a pile of junk," Hannus said.

Another theory placed the bodies at 7th Street and Duluth Avenue.
 
"The only other burial at the time was, they had elected a governor and he died and was buried there so there was three of them in this small cemetary," Blake said.

Right next to the Pioneer Military cemetary, where four Civil War soldiers had recently been buried. But when Hannus drilled more than 300 soil-samples on this property, he found no evidence of any graves. Still the story and the search doesn't end here.

According to history, those four soldiers that were buried at 7th and Duluth were moved to Mt. Pleasant Cemetary and buried in four unmarked graves. Legend has it that Judge Amidon and his son moved with them.

"When they plumbed around the gravesites of the four soldiers from Ft. Dakota, they found no evidence of reburial.  So the headstones are there but there's some question as to if the soldiers are in fact buried there," Blake said.

"Even negative evidence becomes evidence that's important," Hannus said.

Which is why like the road leading up to the historic site, Blake's search for answers is currently at a dead end. Still the legend of the Amidon Affair and the mystery that surrounds it will likely live on for years to come.