"There was [a powder mill] in most of the small towns in Texas that had a good creek at the time, and all of them have been blown up," said Janet Wagner, traveling national historian and chair of the Harris County Historical Commission.

The mill opened in 1861 and included a large water wheel in nearby Spring Creek that was used to generate electricity and help workers produce gear for the Confederate Army calvary and soldiers, blacksmith products and powder for guns during the Civil War. The operation of the mill was short-lived, however, when an explosion leveled the site and killed several employees a few years later.

In 1966, a monument was placed in Spring Creek Park to dedicate the site of the powder mill. The inscription honors three victims who are believed to have been killed in the explosion—Peter Wunderlich, William Bloecher and Adolph Hillegeist, a distant relative of Bruce Hillegeist, president of the Greater Tomball Area Chamber of Commerce.

Wunderlich was a German settler who was a founding member of the Klein area and owned hundreds of acres of land near the present-day intersection of Stuebner Airline and Spring Cypress roads.

Although the inscription indicates the explosion occurred in 1863, recent evidence has been found to suggest the date on the monument is incorrect. After combing through period local newspaper clippings in 2013, Wagner found an article Wunderlich submitted in January 1864—months after he was reportedly killed.

Wagner now believes the explosion took place in March 1864 and is continuing to dig up evidence to determine the exact date. When researching powder mills, Wagner discovered several explosions took place across the country before and after the Civil War that had anywhere from three to 200 casualties.

Wagner has also discovered several firsthand documents and letters from mill employees detailing the extent of the explosion, leading her to believe more than three people were killed in the Tomball incident.

"It's very difficult to know the amount of deaths [at the powder mill] unless we know how many [employees] they had in quantity in there," Wagner said.

Due to the high frequency of powder mill explosions at the time, Wagner said she suspects either Union soldiers or an anti-Civil War group, the Jayhawkers, may have been responsible for the explosion.

In 2013, Wagner and the late historian Don Greene traveled by canoe along the junction of Spring Creek and nearby Powder Mill Gully to view the remnants of the original roadways still visible today.

Since 1864, the site of the powder mill has remained largely untouched and preserved by the Scherer family, who has owned the land for years. The Harris County Precinct 4 commissioner's office designated the site with a marker and continues to preserve its history.