Meyers said that about a dozen Allegheny Power crews were being assisted by at least 30 crews from American Electric Power in Ohio and other utilities.
The storm caused extensive damage at Washington Monument State Park east of Boonsboro, Park Manager Dan Spedden said in a prepared release.
There were no injuries to visitors or park personnel, but fierce winds and driving rain knocked out phone, electricity and water service, the Maryland Department of Natural Resources said in the release.
Fallen trees and branches blocked the main road and the hiking trail to the monument in several places and the museum and water treatment buildings were severely damaged. The park's youth campground was vacant when the storm struck Wednesday.
Spedden said camping reservations for the weekend had been canceled and the park would remain closed while staff assesses the damage.
The National Park Service said that at C&O Canal National Historical Park, between 400 and 500 trees fell across the towpath and park trails in Wednesday's storm.
"Our staff has worked diligently to clear trees brought down by the recent storm so that at least a narrow lane on the towpath is passable," Park Superintendent Kevin Brandt said in a prepared release. "The storm, however, left many large branches in the forest canopy that could fall during periods of high wind."
With that in mind, the park service on Friday issued an advisory recommending that during periods of high winds, park visitors exercise extra caution when walking or biking on the towpath and trails.
Park maintenance crews are working to clear the full width of the towpath and remove trail-side debris and hanging branches, the park service said in a release.
Park service and contractor tree crews would work throughout the weekend, according to the release.
Park officials ask visitors, for their own safety, to heed the direction of the crew members and stay clear of work areas.
The destruction left behind by Wednesday's storm in southern Washington County was caused by straight-line wind gusts of up to 100 mph, according to a National Weather Service representative who surveyed the damage Thursday.
The downed trees and structure damage found in the Sharpsburg, Keedysville and Boonsboro areas all was aligned in one direction, indicative of straight-line winds rather than the rotating winds of a tornado, according to the weather service statement.
While the original Mount Vernon Reformed UCC Church building on Main Street in Keedysville didn't survive the 1862 Battle of Antietam during the Civil War, the current building which dates from 1892, came through Wednesday's storm with relatively minor damage.
"A big oak and a big pine tree fell across the alley and hit the roof," Pastor Delancy Catlett said. "The overhang was broken off over the social room."
The sanctuary on the other end of the building was unscathed, Catlett said. No stained glass windows were affected.
Work already has begun on the repairs, and a tarp covered the damaged roof section. Insurance will cover the repairs, Catlett said.
As for Sunday services, Catlett said that electricity has been restored to the church, so there will be no disruption.
Survey teams determined that tornadoes occurred in Calvert County, Md., and Clarke, Culpeper and Stafford counties in Virginia, the National Weather Service said.
In Washington County, 56 homes were damaged in the storm, Washington County spokesman Norman Bassett said Thursday.
Cooling station available
Washington County Emergency Management and the American Red Cross have announced that a cooling station will be open today from 10 a.m. to 5 p.m. at the Boonsboro Fire Company Annex, Station No. 8, on Md. 67.
Residents of the immediate Rohrersville area can take advantage of the service, as the heat index could be above the 100-degree mark today.
Rohrersville remained without power Friday. Power service was expected to be restored to that area by today at 6 p.m.