Bogoras's name for the whole interior upland, which is what the map says. The book prints it twice and spells it twice — Peˊqul-ñei at 1-047, Peˊkul-ñei at 1-175 — and both times places it north of the Anadyr: a reindeer-breeding group of about 25 camps, distinct from the one on the Belaya (1-047), and the country a large number of wild reindeer stay in after crossing the river (1-175). Neither line fixes an extent. The map does: PEQUL-ÑEI MOUNTAINS is set across the middle of the peninsula, from the head of Chaunskaya Bay eastward, which is the run modern geography calls the Chukotka Mountains — so the identification rests on book-internal evidence and not on the name.

The modern Пэкульней is not this. The name survives on one marginal chain of the same upland — the divide between the Belaya and the Tanyurer, about 300 km, against the upland's 450 — and both of Bogoras's sentences would fit it just as well, since it too lies north of the Anadyr between the White River country and the sea. The map is the only witness that separates the two, and it puts the label over the whole.

The point is Wikidata's centroid rather than a frame, as with Anui Mountains; nothing in the book measures the range.