In the creative ecosystem that is the Upper Valley, we are fortunate to have numerous longstanding nonprofit organizations that put the community at the center of their programming. Two such organizations — Artistree Community Arts Center in South Pomfret and Lebanon’s AVA Gallery and Art Center — will celebrate milestone anniversaries this weekend.

Artistree turns 20 and AVA turns 50. On Saturday, Artistree will host a gala that is sold out, and AVA will host a free 50th Anniversary Birthday Party from 10 a.m. to 5 p.m. at its location in downtown Lebanon.

AVA is planning more events throughout its 50th year, and Artistree hopes to have more “celebratory events” in the fall.

Artistree was founded by Kathleen Dolan in 2003. Originally called Purple Crayon Productions — the name was changed to Artistree in 2010 — programming was directed at children.

“It was just Kathleen,” said Karen Rodis, Artistree’s development director. “She was a one-woman show doing art and music classes for toddlers and preschoolers and their caregivers.”

Now Artistree has a full- and part-time staff of 18 and has programs for people of all ages and abilities. In 2014, the organization moved from Woodstock to South Pomfret, where roughly 30 acres of field and forest have played an important role in Artistree’s development.

“We’re really able to host programs, classes for adults as well as summer camps for kids, where we can integrate nature and art, nature and creativity,” Rodis said. “I think it’s attracted a lot of people who are oriented to nature.”

Sense of place has also played a role in AVA’s 50-year history. The Bank Street building, which the organization has occupied for 23 years, is a mainstay of downtown Lebanon.

AVA was founded on Aug. 24, 1973, by Elizabeth “Lili” Mayor and the late Annabelle Egbert. Originally called Community Gallery, its first home was a barn in Norwich, said Shari Boraz, who became AVA’s executive director nearly two years ago. The organization then moved to Hanover before making its home at the former H. W. Carter & Sons in 1990; it then purchased the building in 2003.

In 1978, the group changed its name to AVA, which stands for “Alliance for the Visual Arts,” according to a timeline on the nonprofit’s website. It is also the year AVA began to offer art classes.

“That’s the backbone of what we do,” Boraz said.

Both Artistree and AVA share a similar ethos: Art (and music and theater) is for everyone. They celebrate the art of doing.

“If you’ve got curiosity, you don’t need to make that goal that ‘I want to be a fantastic artist or craftsman,’ ” Boraz said.

Artistree has quite a variety of programs and camps for children, which can make it appealing to parents who have kids with multiple interests.

“That’s where I think having everything under one roof, that’s an example of how that can be attractive to the community,” Rodis said.

This summer, they’ve had more than 100 summer camp programs, which have served hundreds of kids. Staff are also working on expanding Artistree’s scholarship program.

“We really want Artistree to be a place for everybody,” Rodis said. “We don’t want anybody to not participate because of financial limitations.”

For both organizations, it’s not just about giving people opportunities to create art — it’s also about opportunities to display it. Since the late 1980s, AVA has hosted a juried art exhibition. It takes place every other year, and the next one is scheduled for 2024, Boraz said. In the 1990s, AVA ramped up its art education programs and its financial assistance programs. Each year, elementary, middle and high school students have their work featured in AVA’s galleries. In 2013, it launched The Mudroom, a quarterly community storytelling event.

“Exhibitions and art education and community events, those are the three legs we stand on pretty much,” Boraz said.

Like AVA, Artistree also has beloved regular exhibitions: “MUD (season)” features works of art inspired by the fifth New England season, and “Local Color” features works at what could be the region’s best season.

“I think those community shows are ones that people really celebrate,” Rodis said. “We’ve been doing them for so many years that we really have a dedicated group of people who submit to each of those shows. It’s just lovely.”

Each organization also takes pride in the free and low-cost programs. Both work with people with special needs and older adults.

I’ve heard it said over the years that the Upper Valley is saturated with arts organizations. Sometimes, that word — saturated — can come across in a negative light. It does raise the question of whether the community can support the work these organizations do, not just through attendance but financially. But it could be that the critical mass of organizations is part of secret to their individual success.

“I think arts organizations can kind of feed into one another, too,” Rodis said. “We end up with this patchwork of art opportunities and creative opportunities in the Upper Valley.”

Boraz also spoke in reverence of the people who founded organizations in the Upper Valley after moving here in the 1970s — and nonprofit organizations as a whole. People created the amenities they wanted to see in the region and supported them.

“That’s what I’m benefiting from,” said Boraz, who moved to the Upper Valley from Chicago 25 years ago. “It takes everybody to contribute in their own way for the sustainability of organizations like AVA.”

Note: Detailed histories of both organizations are available on their websites: artistreevt.org/news/were-turning-20-years-old and avagallery.org/history-of-ava.

Liz Sauchelli can be reached at esauchelli@vnews.com or 603-727-3221.

CORRECTION: Elizabeth “Lili” Mayor co-founded AVA Gallery and Art Center with the late Annabelle Egbert in 1973. Mayor’s last name was incorrect in a previous version of this column.