For 17 years, Oscar Mokeme has tried to build an audience for his collection of tribal masks and art and artifacts from sub-Saharan Africa. At times, it’s worked. More than 1 million people have visited the Museum of African Art and Culture, which Mokeme opened on Spring Street in 1998 and later moved to Brown Street. Mokeme also has reached countless schoolchildren, traveling with the elaborately carved masks to schools across Maine.

But with visitation slowing to a trickle, Mokeme plans to convert the collection into a digital, interactive format in hopes of reaching more people across the world. He’s also in discussions with collaborators in Portsmouth, New Hampshire, about moving the collection there to complement the newly dedicated African Burying Ground Memorial Park. That plan would involve closing the physical location in downtown Portland.

The park honors slaves from Africa whose graves were discovered more than a decade ago. Mokeme, a spiritual leader, helped develop the park, offering advice and consulting with city leaders about the graves. The park opened this spring, and Mokeme hopes to find a building nearby to house the collection and take advantage of what he assumes will be more interest in Portsmouth than in Portland for African art and culture.

“We just don’t see many people anymore,” he said Thursday afternoon. “In a day, if we see 20 people, that’s a lot. In Portsmouth, they are getting 200, 300 and sometimes 500 people a day through the park. Having a museum there will increase our ability to reach the audience we hope to reach.”

Thursday evening, about 50 friends and supporters of the museum celebrated its 17th anniversary with a fundraiser at the Brown Street location. The museum opened Aug. 8, 1998.

“We want the organization to grow, and we think these moves will help us become a stronger organization in the future,” interim board chairman Kue John Lor said. “When I mention to people that I work for the African museum, they often say, ‘Oh, what’s that?’ We need to reach a broader audience.”

Susan Barbera volunteers at the museum. She also supports the idea of going digital, but said the idea of closing the doors to the Brown Street museum makes her sad. “I live in Portland, and this place is a jewel,” she said. “I understand the decision, and I think it will be a good thing and help further spread the word, but selfishly I am very sad.”

Mokeme’s plans hinge on the museum’s ability to sell its Brown Street building. The museum will close in Portland if a sale is completed, and the museum will use the money to pay off debt and digitize its collection.

The museum is asking $250,000 for the building. Mokeme estimated it has about $132,000 in debt.

In 17 years, he said he’s taken a salary only for one year, when he received a grant. Otherwise, the museum has operated with volunteers. It needs to generate about $100 a day to sustain itself, “but we’ve never been able to make that,” he said, adding that it’s only because of volunteers “that we’ve been able to hold on for 17 years. It’s a very emotional thing for me to leave the space. It wasn’t an easy decision. If it takes until the end of the year to sell the place, the museum will remain the same until then.”

The museum has about 1,500 items in its collection, including hundreds of masks used in tribal ceremonies. Items range from large, carved wooden masks to small figures, textiles and domestic objects. The oldest mask in the collection dates to 1600 A.D.

The museum will continue its outreach programs, which involve school visits with the masks.

On Friday, Mokeme travels to New York to address a conference at the United Nations about African culture. Part of his goal is to create traveling exhibitions with his collection, enabling museums across North America to show it. That also will help raise money to support museum operations.

He lives in Yarmouth, and has no plans to move.