Officials at the San Antonio Zoo are expanding the 104-year-old visitor attraction, unveiling a US$200m (€172m, £154.3m) masterplan for the historic site.

The zoo in Texas, US, has had its development plan for the next 20 years laid out by its leaders, starting with a new US$1m (€860,000, £772,000) rhino habitat, which broke ground last month.

“We have been working on our master plan for over a well year now and we are excited to build upon the momentum we have gained with recent improvements to the zoo," said Tim Morrow, CEO and executive director of San Antonio Zoo in a statement to Attractions Management.

"Over the next 20 years we will create new large, naturalistic habitats in ways never seen before by our visitors taking advantage of current zoo spaces, as well as unutilised land on our property which will be fully transformed."

Zoo officials say that the masterplan has been created to continue its steady increase in visitor numbers. In 2017, the attraction welcomed more than 1.1 million people, with more than half of those visitors coming from outside San Antonio, creating an economic impact of US$108.6m (€93.4m, £83.8m) for the city.

The zoo currently covers 100-acres and is home to a collection of 3,700 rare or endangered animals across 660 different species.

For its future expansion, the zoo's management consulted with PGAV destinations to devise a plan to make better use of its existing plot, as well as to expand its size and scope for visiting tourists and San Antonio residents alike.

Included in the masterplan is a concept for a safari-style park, with wide open spaces featuring a variety of different animals. New animals could be included in the masterplan following a visitor survey, with gorillas, orangutans and polar bears all requested.

Essential infrastructure work is also included, with major upgrades to plumbing among other improvements necessary for the century-old zoo.

Aside from the rhino enclosure, the zoo has not confirmed when the potential plans could become reality. A spokesperson told Attractions Management that there was "no timeline for any of the other expansions or renovations". The spokesperson also confirmed plans to approach the City of San Antonio, Bexar County, and state leaders to lend financial support to the zoo for various elements of its masterplan.

"Our desire is to give the children and people of San Antonio and South Texas the greatest zoo in the country and increase our educational and conservation impact both here and around the world," said Morrow.

"Over the next 20 years, we will create new large, naturalistic habitats in ways never seen before by our visitors taking advantage of current zoo spaces as well as unutilised land on our property which will be fully transformed. By visiting San Antonio Zoo, you help us secure a future for wildlife."