With 250 members from around New Zealand and the world, the group hopes to inspire more locals to join and learn about the river's history.
Chairman Alan Donald has been a member of the group since its inception in 1988.
"Our main object of the group is to gather as much information on the history of the river."
Growing up in Putiki, Donald said he had a fascination with the river from a young age.
"The reason I first got interested in the river was because of my late father. He passed away when I was 10.
"At 19 years old, we built these canvas canoes and canoed from Taumarunui to Whanganui."
Donald looks back fondly on the week-long journey as they navigated more than 200km of the river.
"Those days, there was no one really around," he said.
As one of the oldest towns settled in New Zealand, Whanganui has a strong history with the river playing a major role in the town's life, Donald said.
"Before the main track went through, this was a highway. If you went from Auckland to Wellington, you came up this river."
He said it is important for locals to learn about the history of the awa, dating back long before Europeans settled in the area.
"Between Whanganui and Taumarunui, there were 60,000 Māori living on the river in different tribes. Those villages and urupa have all been abandoned now."
Donald recalls when the government announced plans to investigate building a 540ft (164m) earth dam at Parikino in the late 1950s.
They first probed at Kaiwhaiki but it was deemed unstable. Drillers then moved to Atene, but came to the same conclusion.
Over the summer months, the Friends of the Whanganui River has a stall at the Whanganui River Markets where the group shares experiences and sells merchandise that showcases the river.
Donald said they are always trying to gather more information on the history of the river and want to share that knowledge with as many people as possible.
"Some people read it and then it reminds them of their own stories and memories."
Being a member of the "Friends" gives you a free copy of the annual as well as access to the various trips the group takes throughout the year.
"Our membership is all over the country - from Auckland down to the South Island. We also have some from Australia and England as well. Half our membership is out-of-towners."
Also in this series:
Welcome to the Club: Wanganui Radio Control Boat Club
Welcome to the Club: Theosophy Whanganui welcomes diversity and deeper understanding
Welcome to the Club: Friends of the Whanganui River
Welcome to the Club: Whanganui Scrabble Club
Welcome to the Club: Wanganui Model Railway and Engineering Society
Memberships cost $35 per year. Anyone interested in joining or learning more can visit their stall at the Whanganui River Markets on a Saturday morning or go to the website https://friendsofthewhanganuiriver.com/.
