Approximately 126 kilometres (78 mi),[4] they form a string of islands and beaches in the southeastern part of the Gulf of St Lawrence.

The rocks that make up the island massifs are of three kinds: horizontal and soft sandstones, of a blood-red color, which give the archipelago a distinctive character.

In the gulf north of the archipelago, cliffs of the reddish and greyish green sandstone, a few hundred feet high and relatively unmarked by sea erosion, give a fortress-like appearance to Île Brion[12] and the Rochers aux Oiseaux.

[14] In the Magdalen Islands, the coastal dynamics are amplified by the wind, with waves most often 0.5 to 2 metres (1.6 to 6.6 ft) high breaking on the coast at a rate of four to seven seconds, depending on their height.

They are subject to rapid erosion (often more than 1 metre, 3 ft 3 in per year) due to the action of frost, ice, waves and sea spray that make numerous openings while undermining their base.

[20] [21] Many of the piping plover's nesting areas are subject to human disturbance or other threats, and it is now considered an endangered or threatened species in all parts of its range.

On the ground, males approach females, stand upright with neck stretched, and rapidly stamp their feet with an odd high-stepping gait.

In 1919 Brother Marie-Victorin used the name Rochers aux Oiseaux during his visit to the Rocks; since 1974, the Canadian Wildlife Service has made them a Migratory Bird Sanctuary.

It offers landscapes characteristic of the Islands: a reddish rocky core, coastal belts reshaped by the wind into dunes, moors, huge beaches and freshwater, saltwater or brackish water ponds.

The islands form the territory equivalent to a regional county municipality (TE) and the census division (CD) of Les Îles-de-la-Madeleine.

Around the mid 19th century as Mi'kmawi'simk (the Mi'kmaw language) shifted, the name changed to become Menagoesenog reflecting islands "battered by the surf."

Recent events that added to the problem included a significant windstorm in November 2018 and the post-tropical storm Dorian that hit the islands in September 2019.

[37] A report in The Washington Post in late October 2019 also indicated that increasing temperatures have led to reduced ice cover over the years, leading to less protection from winter storms.

A November 2019 report from The Washington Post provided these specifics about the effects of erosion:[39]"Some parts of the shoreline have lost as much as 14 feet (4 m) per year to the sea over the past decade.

[citation needed] Tourism is a major component of the islands' economy, as they have many kilometres (miles) of white sand beaches and steadily-eroding sandstone cliffs.

During the winter months, beginning in mid-February, ecotourists visit to observe newborn and young harp seal pups on the pack ice in the Gulf of St. Lawrence, which surrounds the islands.

It was once common for lobstermen to haul in 15,000 pounds (6,800 kg) during a nine-week season that begins each spring, but now it is not unusual to bring home twice that amount, or more.

Hydro-Québec plans to build an undersea HVDC cable from the mainland 225 km (140 miles) away, connecting the islands to the main grid upon completion in 2027.