Already, $10,000 has been given to the Tūrangi Squash Club and another $10,000 to a kohanga reo.
There are plenty more attractions for sponsors to add their branding to, for a cost of $1000 a year - all of which will be donated to charity.
The whole course is based around an exact-scale replica of Lake Taupō, with all the major natural and tourist attractions represented.
Balls drop like skydivers from airplanes while, as luck would have it, actual skydivers fall from the air in the sky above.
With water rushing out of the Huka Falls and Smaug sitting atop Mt Ngauruhoe - or Mt Doom - he explains the concept.
"Everything we are doing here is to pull people off the highway. If you are driving from Palmy to Auckland in a day, you know this is where you are going to give the kids a break."
So there is a big focus on explaining the other attractions on offer, with QR codes and information boards on each of the holes to explain what is on offer around the place.
"It is geographically correct so as you head south this is the Wairakei Bridge, this is Aratiatia Dam and this is the ETA. There is always roadworks on it so this is the humps and bumps. As you cross the bridge there is Huka Prawn Park and Huka Jet."
And the list goes on and on - up the Kaimanawa Range and down the Desert Rd, around the Tongariro Crossing and along the Western Bays.
The final attraction, which is yet to be complete, is a 10-metre-high Māori spear coming out of a rock which will be lit up at night and have a waterfall coming out of it, surrounded by 30 poles.
"It represents how the lake was formed and all those posts, they are the 30 rivers that flow into Lake Taupō so they will all be named and the concrete will be etched with a map of Taupō. And we have got Māori history and volcanic history so people can call in and just sit there without having to pay anything and enjoy it and learn a bit of history as well."
Born and bred in Taupō, Keehan's passion for the place is evident but it's hard to see him sitting still for long, now this project is complete.
So what's the next plan?
"I'm going to go and find a spot in Mexico and sit on the beach I think."