Boasting a full cross-country course, it offers a wide variety of holiday packages to suit both adults and children, which also include hunting with many of the local packs.
There's no doubt that Oliver is one of a kind. By reading the testimonials from people who have spent time in his company, you will get a true sense of the gentleman that he is. No frills, no notions, just a man passionate for what he does best.
"I'm no millionaire, but I love what I do," he says.
Oliver remembers back to his childhood when his love of horses first began. His late father Sean kept a few mares and produced a few young horses to sell at the likes of Ballinasloe.
Throughout that time, it was a busy dairy farm handed down from Oliver's grandfather.
The Walsh family came from a little farm from near Loughrea in Co Galway. "My grandfather used to go from farm to farm, threshing corn. That's how he made his money to buy this place," says Oliver.
"He moved here on November 1, 1929 with his family, two horses and two cars. It was on 80 acres and cost £1,500, which was a lot of money at the time. The farm was rundown, but my grandfather worked hard and developed it as a dairy farm. Back then, a cow was worth £4."
Over the years, further land was purchased and Flowerhill now sits on 280 acres. Much of this is used for the facilities and for grazing for his 60 or so horses and ponies, while 40 acres is set aside for winter barley. "The crop is sold on, while we keep the straw for the horses."
Oliver makes all his own haylage and local farmers often put sheep in the paddocks to graze them down.
As a child, Oliver hunted regularly with some of the local packs, including the East Galway Foxhounds, and it was through his love of the sport that he was one of the founding members of the Co Roscommon Harriers in 1999.
Together with Michael Curley and Dr Morgan McElligott, they restarted a hunt that had been idle for over 50 years.
Oliver was appointed as huntsman, a role he continues to this day.
"The hounds are kept here at Flowerhill and I have great help from my 10-year-old daughter Zara who whips in every weekend. She has been riding since she was four and is a natural in the saddle."
Each Sunday, the hunt attracts up to 50 mounted followers, several of whom could be visitors from abroad. Hunting is hugely popular in Galway and over the years, Oliver has tapped into this market by supplying hired horses for the day.
"We cater for people from all over the world, but Scandinavia is our biggest customer base."
Oliver credits his travel agents with giving him the bulk of the business. "We use HorseXplore in Sweden, Far and Ride in the UK and Zara's Planet here in Ireland.
"I always recommend clients to use the agents as it's a lot more secure. The agent will do everything for you, including looking after travel insurance and accommodation, which is available in nearby Portumna."
In addition to his own pack, Oliver also supplies horses to the North Tipperary Foxhounds, East Galway Hunt and the Grallagh Harriers.
"This time of year is very busy as hunting is in full swing. We also run charity rides for the local community on a regular basis and could have 70 or 80 out at a time.
"There's a lot going on here, but I love what I do. It's what gets me up every morning now at 5.30am."