Thousands of colorful tents lined either side of the North St. Vrain Creek on Saturday, but the campers were not inside.

Instead, they swayed under the clear blue sky to bluegrass artists from around the country during the RockyGrass 50th milestone celebration at Planet Bluegrass in Lyons.

The annual three-day festival sold out this year, filling capacity at 4,100 people, said Zach Tucker, director of operations for Planet Bluegrass.

“Last year was a weird year because everything came together at the last minute,” he said. “We were still figuring things out. This is the first year that we’ve been back to 100% since COVID. It’s this energy and excitement that I was so excited to feel — that I’ve missed.”

Tucker said this year Planet Bluegrass expanded its camping availability and opened the new Shady Grove campsite, near the creek. He said the festival only sold about 200 spots this year but will be able to host about 600 tent campers in the future.

“We are pretty excited to add that because you are a two-minute walk up the hill, and you can hear the music and fish in the river.”

Madi Briones and Jordan Ausman were parked in front of the festival’s main stage Saturday afternoon. They were eager to catch as many performers on this year’s lineup — some of which include Tray Wellington, Big Richard and the Sam Bush Bluegrass Band — as they could.

Briones, of Denver, said she’s been attending the festival for about 15 years. She was introduced to it by her stepdad and has been an avid bluegrass fan since.

“My mom was dating her boyfriend, now my dad, and he was like, ‘This would be a really fun thing and give her a new experience. We could go dance together,’” she said. “That was a way for him and I to bond, so it was a little bit more interpersonal.”

After years of attending, she was able to eventually cajole her friend, Ausman, into joining her, she said.

“I always send messages to her about it,” Briones said. “I talk about how fun it is out here, how it’s just really nice energy — you talk to anybody — make friends everywhere you go.”

Ausman, also a Denver resident, said she was attending the festival for only one day but was enjoying the ambiance.

“Everyone is carefree,” she said. “They are very friendly. It’s just expanding my horizons.”

Under a cedarwood ceiling, away from the main stage, about 100 people sat in anticipation for the band contest. The winner of the annual contest gets to perform as the festival’s opener the following year.

Brian Nordmann sat in the back Saturday, waiting for the show to begin.

Nordmann, 68, of Colorado Springs, said he attended the festival for the first time last year after hearing about it for years.

“The music is obviously the best bluegrass in the country or the world,” he said. “The people are friendly (and) there’s a lot of camaraderie, which is nice.”

As the crowd roared when the first band took the stage, Nordmann said he had no complaints. He was just happy to be there.

“It’s a nice setting, nice music and good people,” he said.