In a short span Sunday night, four people died — the three men riding together and a woman who was riding separately — when they drove their machines into icy open waters. Nobody can recall any time when four snowmobile riders were killed in the same place at roughly the same time.

“It’s hard to believe everything took place in the same location,” said Maine Warden Service Cpl. John MacDonald. He called it “kind of mind-boggling.”

Dawn Newell, 44, of Yarmouth, became the first reported fatality of the season when her machine traveled off a frozen portion of Rangeley Lake and into open water Sunday night. Her 16-year-old son, who was following her on his own snowmobile, jumped to solid ice and got to shore after his sled started crashing through.

While recovering Newell’s body on Monday, wardens found gloves and helmets in the lake believed to belong to three men who had been reported missing at 2:30 a.m. that day. The men had left Carrabassett Valley for a ride Sunday evening but hadn’t returned.

Based on the items and snowmobile tracks leading into the lake, wardens believe the men also rode into the water, MacDonald said.

The men have been identified as Kenneth Henderson, 40, of China; Glenn Henderson, 43, of Sabattus; and John Spencer, 41, of Litchfield. Recovery efforts were put off Tuesday and Wednesday because of high winds and frigid temperatures, which can freeze up sonar equipment and make it unsafe for divers and boat operators.

There are dozens and sometimes hundreds of accidents and several deaths on Maine’s 14,000 miles of snowmobile trails each winter. The record high of 16 fatalities occurred in the winter of 2002-03.

Many of the deaths take place on lakes, with snowmobiles plunging through thin ice or into open waters.

It’s possible the four who were killed Sunday saw that Rangeley Lake was frozen and began riding across at a high speed. Conditions would have been tricky since they were riding after dark and strong winds were whipping up fallen snow.

Snowmobilers often ride at 50 mph or faster on frozen lakes. Riders going that fast have little time to react if water suddenly appears.

Locals know that the middle of Rangeley Lake is usually the last place to freeze, said Clark Allen, a trail manager for the Rangeley Lakes Snowmobile Club.

Nobody should have been out on the lake Sunday night, he said, “but they were from out of town, so they probably didn’t know.”

Multiple snowmobile fatalities aren’t uncommon. In 2003, two snowmobilers were killed when their machines and two others ridden by friends plunged through thin ice on Kezar Lake in Lovell. In 2009, a Pennsylvania couple was killed after hitting open water and sinking into Moosehead Lake off Greenville.

In Salisbury, Vt., two years ago, a veteran snowmobiler, his 24-year-old daughter and 3-year-old granddaughter were killed when their snow sleds broke through the ice on Lake Dunmore.

The Maine Warden Service and the Maine Snowmobile Association held a news conference on Friday urging snowmobilers to ride safely. Half the time was spent talking about the dangers of riding on lakes and ponds, said Bob Meyers, the snowmobile association’s executive director.

Even in the dead of winter, there can be open water on frozen lakes because of currents or places where the ice has broken up, he said.

“If nothing else,” he said, “we hope people pay attention to this and think twice before they head out there.”