The huge rock with two bronze plaques commemorating Omarama district residents who died in the two world wars has been placed in the centre of the town with a flagpole and will be the centre for commemorations in the future.
"It will be a source of pride," Mr Blackstock said.
"It will also remind us of the ultimate sacrifice our community has paid to keep the world a better place."
The memorial would remind present and future generations of that, he said.
About 50 people attended the service on Saturday morning for the dedication and blessing of the memorial, which has the names of three from World War 1 and six from World War 2.
The Omarama Memorial Hall is also dedicated to the memory of men and women who served in wars, but the community wanted an outdoor focal point for services, such dawn service on Anzac Day.
The rock was brought from Birdwood Station, in the Ahuriri Valley, after a search for one that was big enough and had a flat surface on which plaques could be mounted.
The memorial was also the result of a donation by Mary Weatherall, of Cromwell, and the Weatherall family, formerly of Lake Ohau Station.
The blessing and dedication was carried out by the Upper Waitaki RSA Padre, Rev Eric Mattock, of Kurow's St Stephen's Church, after speeches by Ahuriri Community Board chairman Craig Dawson, Waitaki MP Jacqui Dean, Waitaki Mayor Alex Familton and Mr Blackstock.
During the ceremony, the New Zealand flag was lowered to half-mast and it concluded with the Last Post.
