Weather observers in Clear Spring measured 6.75 inches, the highest amount in Washington County. Smithsburg's 3.4 inches was the lowest amount logged.
Frederick City had 7 inches of snow and 10 inches fell in Sabillasville, forecasters said.
As the snow fell, westerly winds combined with cold temperatures frosted some sections of Interstates 70 and 81, Maryland State Police said.
A brief squall Thursday evening dusted some of the roads with snow and Maryland State Highway Administration personnel spent all evening scattering salt and magnesium chloride on the state roads.
Highway workers weren't taken by surprise by the snowstorm, said Mark Benner, shop administrative technician for the state highway administration.
"We're all geared up. This is our specialty," he said.
Today's weather is expected to be cold and blustery with highs in the 30s. Saturday should be partly sunny with highs again in the 30s.
Hagerstown can expect more snow to fall on Sunday, but it's too soon to say just how much, Walston said.
Slick road conditions Thursday morning resulted in reports of 22 minor accidents across Washington County, the Washington County Sheriff's Department said.
Hagerstown City Police said there were few accidents in Hagerstown because of the weather.
The city's main streets were in good condition Thursday evening with some slippery patches on the alleys and side roads, police said.
Dispatchers with Washington County Emergency Services said they hadn't received many calls related to Thursday's storm.
In Berkeley County, W.Va., 12 wrecks were reported, including a tractor-trailer that jackknifed on Interstate 81 about 5:30 a.m., emergency rescue officials said.
A fuel tank fell off the truck during the wreck just south of the Spring Mills exit, spilling about 95 gallons of fuel, said Berkeley County Emergency Services Director Steve Allen.
Two ambulances also had trouble getting to calls around the Eastern West Virginia Regional Airport because of the weather, Allen said.
No major problems were reported in Jefferson and Morgan counties.
Pennsylvania State Police in Franklin County, Pa., said a tractor-trailer hit a car on Interstate 81 near Chambersburg Thursday in an accident that caused no serious injuries but tied up the road for about 15 minutes.
State Police in Chambersburg reported about a dozen motor vehicle accidents in Franklin County. None was serious, police said.
State Police in Fulton County, Pa., reported a single minor accident resulting from Thursday's snow.,
Pennsylvania Department of Transportation crews in both counties were out early Thursday and managed to stay ahead of the storm in keeping the roads clear, spokespersons said.
Skeleton crews were expected to be out in Franklin County all night clearing bad spots caused by snow drifting over roadways, said Perry Goetz, equipment manager for PennDot there.
Staff writers Brendan Kirby and Richard F. Belisle contributed to this story.