This Aimag was cut out of Bulgan Aimag in 1994, to form a new entity together with its capital Erdenet, which had previously been administrated as a federal municipality.
| Sum | Mongolian | Area km² | Population (2006) | Density /km² |
|---|---|---|---|---|
| Bayan-Öndör | Баян-Өндөр | 208.0 | 83,160* | 399.8 |
| Jargalant | Жаргалант | 635.6 | 3,125 | 4.9 |
* - includes aimag capital Erdenet