There exist alternative spellings of the mountain's name, like: 吾妻山 and 吾嬬山 which is read as "Agatsuma-yama" (Mount Agatsuma).
Mount Azumaya was formed between 900,000 and 300,000 years ago by andesite lava flowing out of a stratovolcano.
The famous Sugadaira Kōgen ski area is found on the mountain's southwest (Nagano-) side.
In addition, north of the mountain lies Yonakodaibakufu (米子大瀑布) which is one of Japan's Top 100 Waterfalls.
The mountain is well connected with several hiking trails: Media related to Mount Azumaya at Wikimedia Commons