In 1457 the German-speaking population was forbidden from purchasing land or marrying in the neighboring village of Tersnaus.

After 1776, St. Martin's village church had a German-speaking Prebend though in 1868 it fell back under the authority of Tersnaus.

[2] The municipal coat of arms is Azure, Sankt Martin statant clad as bishop argent and or holding in his dexter hand a crosier and his sinister hand raised in blessing, between seven mullets of the last.

Of the rest of the land, 0.3% is settled (buildings or roads) and the remainder (38.2%) is non-productive (rivers, glaciers or mountains).

It is a scattered settlement on the steep slopes above both sides of the Valser Rhine canyon at an elevation of between 1,000 and 1,700 meters (3,300 and 5,600 ft).

It consists of hamlets of St. Martin, Lunschania (post office), Bucarischuna, Munt, Gadenstatt, Mariaga and Travisasch.

[6] The age distribution, as of 2002[update], in St. Martin is: 7 children or 19.4% of the population are between 0 and 9 years old and 4 teenagers or 11.1% are between 10 and 19.