Campbell felt it was important to talk about the region's history, the early settlers and the pioneers who played a key role in its development.
"As a child, my parents always talked about the early days they had heard from pioneers. As Dad got older, I got more interested and took notes.
"I felt that it had to be recorded. Once we are gone, who is going to know all this history?
"There are a lot of people who I talked to who are no longer with us. When people pass, there is a lot of information that goes with them."
She collaborated with Fowler and together they have spent the last three years crafting the book.
Campbell said it is basically three books in one, with the first part covering the early history of the Birch Brothers, Azim and William, and their journeys from Hawke's Bay over the Gentle Annie into the Inland Pātea area.
The second part of the book talks about the progression of the region from 1920 to 2020.
The third part of the book talks about 'Neighbours across the River', those living on the other side of the Rangitīkei River.
"It was a very, very complex book to write. Years of research, finding photos, interviewing people and making sure the land owners were all on board."
Campbell said trying to put a book together over Zoom over the last two years due to Covid-19 hasn't been easy and pretty stressful.
"But it has been very interesting. There have been a few surprises in the book that I didn't know and I've added to my knowledge as well."
The book is available at Paige's Book Gallery and Paper Plus Taihape. Otherwise, you can email overthegentleannie@gmail.com.