[5] The Marco Polo subspecies Ovis ammon polii was first described scientifically by zoologist Edward Blyth in 1841.

They are called "ra-ma-poy" in Wakhi, the language of natives of the Khunzerav region round the high Khunjerab Pass between Pakistan and China.

[4] They begin growing 15–20 days after the sheep are born, and their growth in length is most pronounced during the first year.

[25] However, the shepherds in the area do not generally have access to veterinary care for their animals, and it is possible that these could transmit diseases to the wild sheep.

[26] Most Marco Polo sheep live in the Pamir Mountains region adjacent to the borders of Afghanistan, Pakistan, Kyrgyzstan, Tajikistan and China.

[32] Terrain ruggedness and annual mean temperature are the two major factors that affect their distribution.

[36] O. a. polii males have been noted to rise up on their hind legs when they clash with opponents, which is not common in lowland sheep and similar to the fighting habits of goats.

[38] The males commonly emit grunts while fighting and often chip their horns or break their noses.

[36] Shackleton calls this phenomenon "lip-curl" and describes it as "raising the head with the mouth open and upper lip curled back.

[39] In 2008, it was estimated that American hunters paid an average of $20,000 to $25,000 for an expedition to hunt a Marco Polo sheep.

[11] Their population density has been recorded as fewer than two animals per 1 square kilometre (0.39 sq mi).

[42] In 2024, an American man pleaded guilty to illegally importing body parts of Marco Polo sheep to create clone hybrids, which he planned to sell to private hunting reserves in Texas.

The Khunjerab National Park was established primarily as a means to protect the Marco Polo sheep (as well as snow leopards and bharal) living in the area.

Because of this, the International Union for Conservation of Nature commissioned Norwegian biologist Per Wegge to do a wildlife survey of the park in 1988.

[47] He therefore proposed that the park be reclassified, allowing grazing and commercial hunting, with the profits going to local residents.

[50] Schaller, among others, then proposed an international reserve in 1987 to combat the problem, but the effort was stalled due to political difficulties.

[51] His mission was to found a park straddling the borders of China, Pakistan, Afghanistan and Tajikistan in which the sheep would be protected.

"[50] According to Marco Polo's original description of the sheep, the horns (which he described as "as much as six palms in length")[4] were used by shepherds to craft large bowls, or to build pens for the flocks.