Utility crews continued working Friday across much of Maine to reduce the number of power outages caused by a pre-Thanksgiving snowstorm, but many customers were expected to remain in the dark a while longer.

As of 8:30 a.m. Friday, Central Maine Power reported 28,300 still without power, down from 104,000 at peak.

Homes and businesses in York and Cumberland counties accounted for nearly three-fourths of all outages – 11,813 customers in York County and 7,637 in Cumberland County.

In York County, South Berwick was hit hardest, with 1,929 outages among 3,155 customers. York was second with 1,414 outages out of 10,107 customers. In Cumberland County, CMP reported that 2,348 of Harpswell’s 4,442 customers were still without power.

CMP also reported outages for 2,794 customers in Sagadahoc County, including 599 of Georgetown’s 1,165 customers. Nearly every Georgetown customer had been without power during the day.

In general, outages were fewer to the north. Emera Maine, the largest supplier of electricity in northern Maine, reported fewer than 600 customers without power at 4 a.m. Friday, with 425 of those in Hancock County.

Despite efforts by utility workers and an emergency proclamation by Gov. Paul LePage that allows crews from Canada to work longer hours, CMP spokesman John Carroll said many homes would likely remain without power through Thanksgiving and perhaps into the weekend.

Carroll said about 600 CMP employees reported to work on Thanksgiving, with line repair crews starting at 5 a.m. About 70 Canadian utility workers also were expected to help.

He said the milder weather, clear roads and daylight aided progress.

One of the biggest challenges was making sure the line workers were fed.

“Most sandwich shops are closed today, so it’s more challenging to get food for the crews,” Carroll said. “We’re scouring the cities and towns to round up food, but I don’t think many of our crews will have a hot Thanksgiving dinner tonight.”

On the plus side, he said, CMP workers in the field receive lots of thanks.

“Everyone would like to be home, but people also get a lot of satisfaction knowing that their efforts are so appreciated by our customers,” he said.

A major concern during prolonged power outages is the use of generators. Maine’s Department of Health and Human Services urged users to be safe with their generators and guard against carbon monoxide poisoning, which can be fatal.

The storm, which began early Wednesday in southern Maine and stuck around through the evening, dumped 8 to 15 inches of wet, heavy snow that pulled down trees and utility lines.

The most snow was reported in Lewiston, which got 15 inches, said Mike Kistner, a meteorologist with the National Weather Service office in Gray. Portland got 8.5 inches.

In York County, amounts were in the 12- to 14-inch range, but the water content was particularly high.

The next few days will be uneventful, Kistner said, but temperatures are expected to remain cold.

“I don’t think we’ll see much melting, and all that wet snow left behind is probably going to turn into a block of ice,” he said.

Most afternoon and evening flights in and out of Portland International Jetport on Wednesday were canceled. Flights were arriving on time Thursday morning, but some departures early in the day were canceled.

The snowstorm caused outages along Amtrak’s Downeaster train route, which were expected to cause significant delays Thursday.

The city of Portland imposed a “yellow zone” parking ban from 10 p.m. Thursday through 6 a.m. Friday to clear snow.

Not everyone was snowed in by the storm.

Hundreds of runners braved the icy streets of downtown Portland for the 33rd annual Thanksgiving Day 4-miler. Most wore hats and gloves. Some pushed toddlers in jogging strollers. One woman ran in a head-to-toe turkey costume.

Chelsea Fyrberg was among the runners. She said the route was slippery, but “the sun was shining.”

When Fyrberg left her house in Gorham, she was still without power. She didn’t know how long that would last.

“The turkey is still in the fridge,” she said. “We were supposed to eat at 1 p.m., but that’s not going to happen. Maybe tomorrow is more realistic.”

Anna Kendrick, an Academy Award-nominated actress from Portland best known for her role in the film “Pitch Perfect,” posted snowy photos on her Instagram page, signing off with 207, Maine’s area code.

“No power, no heat, but we’ll eat canned cranberry sauce and be pleased as punch,” she wrote.

Staff Writer Scott Dolan contributed to this report.