Flames raged through 10,000 feet of swampy woods Monday afternoon just off of Fish Hatchery Road. Madison Fire Department responded immediately to a report of fire at UW-Madison’s arboretum with forces and equipment so extensive that traffic on Fish Hatchery was obstructed for an hour, as reported by the Wisconsin State Journal.

The 60-year-old prairies at the arboretum, which encompasses 510 hectares, are used for research.

As of Monday evening, the cause of the fire was undetermined. Assistant Fire Chief Matt Wright told the State Journal the fire’s origin may never be known because evidence of either arson or natural causes would have been burned.

Officers used the foot-deep water in the swampy marsh setting to put out some flames and stop the fire from spreading by submerging dead trees. But, Wright said, it was “difficult,” “labor-intensive work” to move through the swampy land.

The fire started at about 2 p.m.
— compiled from reports