The tornado that destroyed homes and buildings in two Pierce County communities spun up just north of Ellsworth before continuing on for about 12 miles.

The National Weather Service released those results Thursday, along with confirmation that the tornado was an EF-1. That tornado classification - based on wind speeds and destruction - is on the smaller end of the Fujita scale, which ranges from EF-0 to EF-5.

Alexandra Keclik, a NWS meteorologist, said Wednesday’s tornado in Pierce County reached peak wind speeds of 105 mph.

The twister developed about six miles north of Ellsworth at about 4:25 p.m., Keclik said, and continued on an east-northeasterly path until retreating two miles southwest of Spring Valley. The event ended at about 4:45 p.m.

Keclik said the tornado stayed on the ground for the duration of its presence.

Pierce County Emergency Management Director Gary Brown said between 30 and 35 properties were affected by the storm. That number could rise as assessment teams continue their work, he said, adding that the towns of Martell and Gilman appeared to be the most affected.

Homes, farm structures, commercial buildings and garages were among the damage reports Brown said he's collected so far.

“A lot of properties have significant damage,” Brown said. “It appeared like it was a very powerful storm.”

Reports of damage in Spring Valley might stem from debris that blew in from outside the community, he said.

Kyle Kriegl, an official with the Eau Claire chapter of the American Red Cross, said the organization hasn’t been requested to assist any residents, but “we stand ready to help for anyone that needs it.”

The storm packed heavy rains as well, dropping a confirmed 2.27 inches on River Falls. The weather service also reported penny-sized hail during the storm.