Sibling revelry gripped the opening day of the U.S. Cross Country Championships in Houghton, Michigan.

The Patterson family of Anchorage celebrated two national champions when siblings Caitlin and Scott captured victories Sunday in the first ski race of a week-long series.

Scott Patterson, who will turn 24 at the end of the month, and Caitlin Patterson, who will turn 26 at the end of the month, took decisive wins in the classic-technique races.

It was the first national championship for both skiers and the first medal of any color for Scott. Caitlin boasts a complete set of medals – bronze from 2014, silver from 2015 and this year's gold.

Both won decisively.

Scott topped the men's 15-kilometer race by nearly 20 seconds, finishing in 40 minutes, 26.2 seconds. He led a group of five Alaska men into the top 12.

Caitlin enjoyed an even bigger margin in the women's 10-K classic, forging a 36-second lead over her nearest competitor. She was one of four Alaska women in the top nine and one of three in the top five.

Both bronze medals went to Alaska skiers -- Girdwood's Chelsea Holmes in the women's race and Anchorage's Eric Packer in the men's race. Packer finished fourth in the men's race, but because one of the skiers ahead of him was Canadian and therefore ineligible to win a medal at the U.S. championships, the bronze went to Packer.

Nine Alaskans cracked the top 10, including seven who ski for Alaska Pacific University – a group that includes Scott Patterson, Holmes and Packer.

Caitlin Patterson trains with Vermont's Craftsbury Green Racing Program, and Silas Talbot, 12th in the men's race, skis for the Alaska Winter Stars.

The Pattersons grew up in Anchorage skiing for Jan Buron, their coach with the Alaska Winter Stars and at South High, where Caitlin was the state Skimeister in 2007 and Scott was a three-time Skimeister from 2008-10.

Both were NCAA All-Americans at the University of Vermont. After college, Caitlin remained in Vermont and Scott returned home and joined the APU ski team. Last summer, Scott won the Crow Pass Crossing backcountry marathon with one of the fastest times in race history.

According to Scott's blog, both were training on minimal conditions in December – Scott on Kincaid Park's 3-K loop and Caitlin on a 1-K loop back east. Then they traveled to Bozeman, Montana, where their parents recently bought a home, Scott wrote. There, they found abundant snow and were able to get in good training while celebrating the holidays.

Scott headed to Houghton feeling fit and confident – in early December, he won a Super Tour mass-start classic race in Idaho. Even so, it took him three or four kilometers to find his race pace in Sunday's individual-start race.

At about the 4-K mark, he said in a recorded interview, he learned he was in fourth place, about six seconds behind the leader.

"That really jumped me," he said. "I really got going climbing up the next few hills, and by 7.5 K I was in the lead."

Taking second place was Canada's Kevin Sandau (40:45.4), just ahead of Northern Michigan's Adam Martin (40:47.0).

Packer was fourth (40:58.1). Other Alaskans in the top 15 were Lex Treinen (8th, 41:18.9), David Norris (11th, 41:24.5) and Talbot (12th, 29.1).

Caitlin Patterson's closest competition came from Craftsbury teammate Kaitlynn Miller, second in 29:34.4. Holmes earned third place in 30:01.0.

APU's Becca Rorabaugh placed fifth in 30:07.4 and Rosie Frankowski finished ninth in 30:51.2.