No need to go to Mongolia to build your own ger. This SITE will give you all the info you'll need.
The Mongolian Ger (describing a Mongolian's tent as a yurt may offend his/her national pride) is a versatile dwelling with a proven pedigree, being home to the nomads of central Asia for many centuries. The oldest complete yurt yet discovered was in a 13th century grave in the Khentei Mountains of Mongolia. Discoveries at Pazaryk, Southern Siberia indicate that the technology to make yurts was in use during the 4th century BC. The BBC Horizon series "Ice Mummies" suggests that yurts were in use at this time. Throughout this time the design has changed little, the ger being perfectly suited to a nomadic lifestyle in one of the worlds most inhospitable climates, with high winds rain and snow, where winter temperatures regularly fall to -50ºC. To this day it is still the preferred home to the majority of Mongolian people, the suburbs of the capital Ulaan Baatar consist entirely of gers. The use of the other two yurt types has declined greatly this century.