In 2014–2015, 13,477 Mongolian schoolchildren (5833 boys and 7644 girls from different regions of the country), aged 8–17, were subjected to a comprehensive biological study. The program included 50+ anthropometric and anthroposcopic traits. Out of this set, bodily dimensions and functional parameters were used for the present paper. Their analysis was carried out among residents of mountain-taiga, steppe, and desert zones, which are still the main ecological niches of Mongolia. The urban sample (the best known Mongolian population, which included only subjects born and living in Ulaanbaatar) was used as a control group. The urban children and adolescents, as well as those living in the mountain-taiga zone, are characterized by maximal average values of the parameters. In the capital, these parameters are mostly affected by the living conditions, which are the best, confirming the results of previous studies. At the same time, the stressful urban factors account for higher indicators of the hemodynamic system in urban schoolchildren. The resemblance of these characteristics in steppe and desert dwellers results from relatively similar climatic conditions and physical stress patterns.