It is located in the Palisades, a group of prominent rock peaks with a few small glaciers on their flanks.

Mount Sill is located 0.6 miles (1 km) east of North Palisade, the high point of the group.

The two peaks are connected by a high, rocky ridge, on the north side of which lies the Palisade Glacier.

[8] The mountain is called Nen-i-mish ("the Guardian of the Valley") by the Indigenous Northern Paiute people.

[6][8] Its English name was coined, in 1904, by Joseph LeConte, a noted mountaineer, in honor of American poet Edward Rowland Sill.