Property developer the Granger Group has turned its attention from health care and senior living complexes to produce plans for a US$500m (€440m, £323m) theme park and resort development in Williams, Arizona, predicted to attract four million visitors annually.

Included in the designs are a selection of rides, an adventure course, a wilderness area, an amphitheatre, hotel and spa and themed restaurants.

“We think it's going to work very well and we think it's going to be a stepping stone to another project in the Phoenix area, and that's going to be a stepping stone to the whole concept of international travel, understanding that this is the Grand Canyon state,” said Gary Granger, president and CEO of the Granger Group.

If approved, state legislation allows for the Arizona theme park district board to issue as much as US$1bn (€881m, £648m) in bonds to pay for any number of theme parks inside a certain land space approved in December by the the Williams City Council, the Phoenix City Council and the Coconino County Board of Supervisors.

If the proposal from the Granger Group is accepted, 9 per cent of revenue generated would be used to pay off the initial capital investment. The proposal predicts such a park would generate around US$125m (€110m, £81m) annually for gross revenue.

Initial plans for the theme park include Route 66, wild west, mining and Navajo Nation themed areas. The group also promises rides, interactive exhibits, animal encounters, stunt shows, gold panning, archery, rock climbing, kayaking, ziplining, mountain biking, and hot air balloon rides.

The Granger Group is currently conducting a feasibility study for the project, which is due in April. The developer is also yet to finalise an operator for the project and in May will focus on refining the scope of the plans.