The former Guiseley boss and right-hand man Danny Boshell have signed three-year deals at the Horsfall - and they want to build something special.
Avenue rarely moved from the bottom of the National League North table in the 2019-20 campaign but there were encouraging signs towards the end.
A win at then leaders King’s Lynn showed improvement and back for his second spell after leaving a year ago, Bower wants the team to be looking towards the top half next time.
He told the club’s website: “After what has been a difficult last 18 months, I’m positive that we now have a structure in place that can build a long and sustainable future both on and off the pitch.
“The proposed ground developments are exciting and it feels like we are entering a new beginning with a real focus and professional approach behind the scenes.
“I’m looking forward to the challenge and both Danny and I know we can count on the supporters to get behind us and help us through these uncertain times, in the knowledge that there is a solid plan and commitment in place to grow the club over the next few years.”
Owner Gareth Roberts added: “I am really pleased that Mark and Danny have extended their contracts, we are lucky to have local lads with great coaching ability and whom understand and know the club.
“After a tumultuous season we wanted to steady the ship and have some strong foundations to build on.”