In 1942 the government forced out the remaining families and burned down their homes to prevent their return.
Descendants maintain their connection with the valley through the Friends of the Mangapurua community group.
A history highlight has been the publication by Raewyn West in 2017 of the 360-page history Remembering Them.
In the valley, the Friends accomplishments include marking each farm property its family names and establishing an Anzac Memorial.
At 11am on Sunday, 80 participants gathered for the ceremony at the Anzac Memorial.
Parking their cars at the Ruatiti Rd end they had to journey 8km to the Mangapurua Trig.
For most the trip to the site along the steep winding former road route was quite an adventure - whether done by foot, mountain bike or quad bike.
This time the youngest was an 8-month-old accompanied by the oldest, her 94-year-old great-grandmother.
The old road route today is busy with 16,000 visitors each year, of all ages, enjoying it as the Mountains to the Sea cycleway, the Mangapurua Valley hike, the Te Araroa Trail, or access to hunt for pigs and deer in the distant back country.
In 2017 Mike & Raewyn West instigated a project to create this memorial site to mark the centenary of the first of the soldier settlers arriving on the land.
The inspirational site offers provides panoramic views over the rugged bush lands that were proposed for farms.
The memorial includes a striking sculptured monument, a flagpole, and a shelter with story panels naming the 96 soldiers with their photos.
At each gathering one descendant family has the opportunity to present a history highlight.
This time the McIntyre family featured a letter written in 1925 from their grandfather in the valley to his wife who was in hospital in Whanganui having their second child.
Jack said he would be happy with whatever name Irene chose for the baby and that his plan was to go to Whanganui and accompany her back to the valley once he had finished the shearing.
That wool clip was important for the new baby; it would be the only farm income for the family for that year.