The first setback came in 1936, when - at the request of the municipality of Scuol - the Tavrü valley was excluded from the Park.

In 1957, following a heated campaign, the Swiss people voted in favour of granting a concession to the Engadine Power Company to exploit the water power of the Spöl stream. This had long-term consequences on the stream’s ecological system.

The former National Park House in Zernez was inaugurated in 1968. Since 2008 this building houses the municipality offices, as well as the kindergarten.

New National Park regulations were introduced in accordance with federal law in 1980, and ratified on a cantonal basis in 1983.

2000 saw the enlargement of the Park, with the integration of the 3.6 square kilometre area of the Macun lakes. The idea of creating an outer zone around the Park was rejected by the local population.