Contents of stable isotopes of oxygen (δ¹⁸O), deuterium (δ²Н) and deuterium excess values (dexc) in Late Pleistocene massive ice and ice wedges (11-YuV-2) and in the Holocene ice wedges from sandy loam under peat deposits (11-YuV-1) in the upper Mordyyakha River, 537 km of the Ob-Bovanenkovo railway road.The ice isotopic composition was determined at the Laboratory of Stable Isotope Geochemistry (Lomonosov Moscow State University) using a Delta-V mass spectrometer with a standard gas bench option. δ¹⁸O measurement implied equilibration of analyzed samples with CO₂ over 24 h, while the δ²H measurement was carried out using a platinum catalytic agent over 40 min. The values are presented in δ‐notation in per mil (‰) relative to the Vienna Standard Mean Ocean Water (VSMOW). For measurements international standards V-SMOW, SLAP and MSU own laboratory standard (snow of the Garabashi glacier) were used. Analytical precision was ±0.1‰ for δ¹⁸О and ±0.6‰ for δ²H.