When Andrew Lindbloom started a Polar Plunge Club three years ago, it was just for “fun.”

He said there were no events in Durango that didn’t center around drinking and partying, so he rounded up some friends to jump in the Animas River in the middle of winter. Even during this warm spell, that water is around 40 degrees.

“Fun.”

And why not do it on Valentine’s Day?

“Why not have couples take the plunge together,” said Lindbloom, who meant it figuratively and literally.

Lindbloom and his girlfriend, Melissa Mahan, polar plunged together, then Lindbloom dropped to one knee and proposed to Mahan. She said yes, then they plunged into an engagement together.

For the Polar Plunge Club, Lindbloom soon saw that it could be more than just a few friends stripping down to their skibbies and jumping into the snowmelt.

Enter the inaugural Polar Bear Plunge for Charity.

“We decided to change it from just a bunch of goofballs jumping into the river to a charity,” Lindbloom said.

Meagan McCoy, a coworker of Lindbloom’s, has a sister with multiple sclerosis. A friend of Lindbloom, La Plata County Sheriff Sean Smith said he would plunge for his sister, Dawn Michelle Smith Perre, who succumbed to amyotrophic lateral sclerosis or ALS, also known as Lou Gehrig’s disease, in January.

While ALS is a rare progressive neurodegenerative disease, MS affects the central nervous system. Both are debilitating, and combating them needs funding. Hence, this year’s charitable plunge for ALS and MS, a cause Lindbloom will stick with. The plunge, Lindbloom said Saturday night, raised $410.

“It’s a good thing to support the research,” McCoy said.

“It just has all the more meaning at this point,” Smith said. “That’s why we’re here.”

Smith’s wife, Traci, said her uncle also has MS.

“Both diseases have been rare in the past, so it’s been hard to raise money for them,” she said.

Stashes of towels were piled around the old boat-launch site off 32nd Street, where about 30 people lined up in two groups, each rushing the river and each of their faces contorting with the inevitable cold shock they voluntarily gave themselves. Per the rules, you had to go all the way under.

Lindbloom and his girlfriend were the last out of the second group, when Lindbloom took a knee on the sand at water’s edge.

“I knew something was going to happen,” Mahan said.

Friends held signs on the beach, and Lindbloom proposed.

“Popping the question was easy,” Lindbloom said. “I was more scared about the water.”

bmathis@ durangoherald.com