With four years as a regular in the British army and another 20 years as a territorial, Mr Ellis has had extensive military experience, including time spent in Germany as troops were deployed to the Gulf war.
"The troops here in the Tararua were trying to win the hearts and minds of the people and military personnel were rapt the way the people of the district had taken to the Army coming in," he said.
But it wasn't just military personnel involved in the exercise. Residents also got stuck in and played a part.
Commander of 1 New Zealand Brigade Colonel Chris Parsons said having the community involved was essential and appreciated.
"The people of the Tararua were vital to the success of the exercise.
"They had local knowledge and were very supportive of what we were trying to achieve. Their input was invaluable," he said.
In the south, Mauriceville beef and sheep farmer David Cameron allowed insurgents to lie low in his wool shed as they tried to disrupt soldiers seeking to flush them out.
He said it was easy to see how hard it would be for military forces trying to identify insurgents who had befriended locals in real conflict situations.
"Insurgents who got on with locals would be very hard to beat. I have a totally new understanding and appreciation for what our defence force does," he said.
Mr Cameron said New Zealand soldiers got on well with locals when they were deployed.
"The guys we had on our farm got stuck in, got on with everyone and were a credit to the military. I was pleased to be able to help and be part of such an important training exercise.
"It's important our guys get to train in the right environment so they can do their job when they go overseas."
But it wasn't all easy going for the troops, with two US marines from Hawaii having to cope with the elements when snow and freezing conditions hit, Mr Ellis said.
"All the troops were likeable and saw plenty of the Tararua, patrolling in their LAVs (light armoured vehicles) at Pongaroa and as far out as Herbertville and Akitio," he said.
"We even had rebels holed up in the Pongaroa Hotel."
Although the troops have left, the Tararua District Council is working with the defence force to find a couple of local projects they can work on together.
"One of the those projects is the old swing bridge at the Eketahuna Camping Ground," Mr Ellis said.
"It's been great for the Tararua to have these troops here and they've spent money in our district too.
"They're also keen to come back in smaller numbers, as they see the district as a very good training ground."
Exercise Alam Halfa 2013 was the precursor to Exercise Southern Katipo, to be held in the South Island this year.
