Chromosome numbers are given for 58 plant taxa of the Yukon Territory, especially from the unglaciated areas in the Ogilvie Mountains. The chromosome numbers of the following taxa were previously unknown:Rumex arcticusTrautv., 2n = 40;Claytonia arcticaAdams, 2n = 10;Arenaria arcticaStev., 2n = ca. 80;Arenaria physodesFisch.exDC., 2n = 66;Melandrium taylorae(Robins.) Tolm., 2n = 48;Ranunculus gelidusKar. & Kir., 2n = 16;Ranunculus sceleratusssp.multifidus(Nutt.) Hult., 2n = 64;Ranunculus purshiiRichards., 2n = 64;Thalictrum sparsiflorumTurcz. var.richardsonii(Gray) Boivin, 2n = 14;Chrysosplenium wrightiiFranch. & Sav.,n = 12 and 2n = 24;Saxifraga adscendensssp.oregonensis(Raf.) Bacigalupi,n = 11;Saxifraga punctataL., 2n = ca. 84;Saxifraga radiataSmall,n = 13;Dryas alaskensisPorsild, 2n = 18;Geum rossii(R. Br.) Sér., 2n = 70;Potentilla ledebourianaPorsild,2n = 28;Oxytropis huddelsoniiPorsild, 2n = 16;Epilobium ciliatumRaf., 2n = 36;Penstemon gormaniiGreene, 2n = 16;Synthyris borealisPennell, 2n = 24;Arnica lessingiiGreene, 2n = 57.