Two projects in and around the Grand Canyon – the famous US landmark that welcomed nearly 4.6 million visitors in 2013 – are raising concerns about how much more development the attraction can withstand.

The first project, led by the Italian company called Stilo Development Group, is proposing 140 acres of commercial development, approximately 2,700 housing units, a spa, a working ranch that accepts guests, water park and a cultural centre in Tusayan. This project, called The Tusayan General Plan 2024, was approved by the local council in April to capitalise on its location as the main gateway to the canyon’s southern rim, according to Travel Weekly.

The second project, Grand Canyon Escalade is being managed by Confluence Partners – a company formed specifically to oversee the plan. Set to be located on a reservation that borders the eastern edge of the Grand Canyon National Park, owned by the Navajo tribe, the venture includes a tram from the canyon rim to a location near the Colorado River, an elevated walkway at the bottom of the canyon, a discovery centre, lease sites for hotels and other retail parties.

A group of Navajos has formed an opposition movement against the Escalade project called Save the Confluence (referring to the confluence of Little Colorado and Colorado rivers). The group claims the project endangers the east rim’s fragile ecosystem and that none of the project’s anticipated revenue will be used to help residents.

The superintendent of the Grand Canyon National Park, Dave Uberuaga, said both projects pose different threats to the canyon. The Tusayan General Plan will be developed on a site with limited water supply that local wildlife rely upon. The Escalade project concerns Uberuaga because over-capitalisation on the popularity of the Grand Canyon will damage the landmark.

“There’s only one Grand Canyon in the whole world, and every increment of change and development takes away from that experience,” said Uberuaga.