The Rose City Riveters fan club claims three sections of Providence Park for Thorns matches. (Don Ryan/Associated Press)

The energy. The atmosphere. The roar of the 20,674 fans at Providence Park on March 8, 2014. All of it hit Emily Menges as she watched the Portland Timbers’ home opener from a suite. She would be playing in this same arena in about two months, and the fan support for the Timbers of the MLS was insane.

But that’s the men’s game, figured Menges, who was drafted in January 2014 by the Portland Thorns of the National Women’s Soccer League draft. She returned to Georgetown University to finish classes and graduate before relocating to Portland for the start of the Thorns’ season.

When she stepped onto the field for the Thorns’ home opener, April 26 against Kansas City, she was “blown away that was basically the same amount of people.”

The seats at Providence Park were largely filled by a crowd of 14,124. The average attendance for home games her senior year at Georgetown was 358.

“I’ve never seen anything like this before,” Menges, a starting defender now in her fourth season with the club, said in a recent phone interview. “There was nothing that even compared to what they had out here.”

Nothing in the country can compare to the home support given to women’s professional soccer in Portland. Through five games this season, the average attendance for Thorns home matches is 16,430. The Orlando Pride ranks second in the NWSL with an average of 8,299 through three home games. The Washington Spirit, which will host the Thorns on Saturday night at Maryland SoccerPlex in Boyds, averaged 3,112 in its first five matches.

Why does Portland receive this much support? It’s not the biggest city with an NWSL team: Houston, Seattle, Washington, Boston and Chicago all boast larger populations.

“I think it’s a combination of a few things,” Mike Golub, president of business for the Timbers and the Thorns, said in a phone interview. “First, we have a great, rich soccer history here. Second, we have a really, really special venue. We have a great organization. But what it really comes down to is you have a city who loves their team.”

The Thorns have reached at least the playoff semifinals in three of the four seasons since the NWSL was founded, claiming the championship in 2013. That’s in no small part to their advantage at Providence Park, where they have lost only five times since 2015 and own an all-time record of 28-13-8 in league play. This season the Thorns are 3-1-1 at home and 4-3-2 overall (15 points), in fourth place in the 10-team NWSL standings heading into Saturday’s game at Washington (2-5-2, eight points).

Visiting teams know how hostile it can get at Providence Park, a soccer-specific venue with a capacity of 21,144, second largest for an NWSL stadium behind Orlando. When Thorns Coach Mark Parsons held the same position with the Spirit he would look at the preseason schedule and circle the game at Portland.

“The first time I experienced it, you try to stay focused, you try to focus on the game, but at the same time, it’s hard not just to take it all in and be blown away by the mass support,” Parsons said in a phone interview. “But it’s real support, it’s not just numbers sitting in the stands. They are singing nonstop all around the stadium.”

The majority of the singing comes from the north end of the stadium. A black banner hangs there that reads: “Welcome to the North End, home of the Timbers Army and Rose City Riveters.”

Members of the Thorns supporters’ club hold scarves that say, among other things, “Thorns Alliance.” They wave flags. They blow horns. They bang drums. They hold tifos. They sing, as Parsons said, nonstop and chant with curse words, even if children are present.

“What we’re doing in the Rose City Riveters is not necessarily family-friendly,” said Sunday White, a capo for the Riveters, which means she is in charge of leading the chants and keeping the crowd cheering. You can’t miss her. She wears her hair in a tall mohawk that’s always colored differently.

White has been a capo since the Riveters formed in 2013, shortly after the Thorns were announced as one of the eight founding members of the NWSL. About 45 people attended an initial meeting to create a fan club for the Thorns as fast as they could, “so we could be functional and supporting them by the first game,” White said.

They came up with the name Rose City Riveters a few months later, an homage to Portland’s nickname as well as the Rosie the Riveter icon. Ever since then, they have gathered for every match at the north end of the stadium, claiming sections 106, 107 and 108. Like the game against the rival Seattle Reign on July 30. Both teams were missing key players to the Olympics, but 19,231 fans still showed up. The game was scoreless for 73 minutes. Then in the 74th minute, Nadia Nadim received a pass in the box from Mana Shim. She headed the ball into the back of the net. The crowd erupted.

“The noise from the crowd that moment, I don’t think I’ll ever forget,” Parsons said. “I don’t think I’ve never heard a noise like that.”

Highlights from the match show the Thorns piling on top of Nadim after her goal. Then a camera scanned the crowd. It’s there that you see White, in a tie-dyed shirt and purple mohawk, standing in the north end.

She waved a black skull-and-crossbones flag.