Alisha Roemeling, Statesman Journal Tammy Stillwell, of Langley, Washington, was part of the cavalry and was preparing to head out to the battlefield when her horse took a turn into the woods, said Scott Ingalls of the Northwest Civil War Council. Stillwell was knocked off her horse by a tree branch and fell to the ground, Ingalls said.
The incident took place around 3 p.m., said Chris Havel, spokesman for the Oregon Parks and Recreation Department. A number of people involved in the event came to her aid, keeping her cool and calm until emergency services arrived around 3:30 p.m., according to the Woodburn Fire Department.
"She was conscious and alert the whole time, while she was laying there and when she was transported," Ingalls said.
Stillwell was taken to Salem Hospital. She went into emergency surgery Sunday to repair internal bleeding but died during surgery.
"I don't know if that was from her injuries or if that was from the surgery," Ingalls said.
The community at the re-enactment was stunned.
"Oh they're devastated," Ingalls said. "We've never even had a serious injury."
Stillwell's Facebook page shows her as an avid horseback rider. One friend posted on her page that she was riding a horse named Maxx at the time of the accident.
Oregon State Police spokesman Lt. Bill Fugate said Monday that because Stillwell died at the hospital, the agency would not be investigating.
Ingalls said the re-enactors group would be conducting an investigation, as would the Oregon Parks and Recreation Department.