On January 1984, Oyama Sankei became a national significant intangible folk cultural asset in Japan. No one really knows when this festival began, and there is much debate whether it started in the Kamakura period or the Edo period. Regardless, it is safe to assume that this festival started a really long time ago, but is nonetheless a very important cultural event to the people of the Tsugaru region.
This festival is held to pray for the safety of family members and for an abundant harvest, since Late-August marks the beginning of both rice and apple farming in this region.
The festival is broken into three distinctive parts: 向山(むかいやま) mukaiyama、宵山(よいやま) yoiyama、朔日山(ついたちやま) tsuitachiyama.
The first part of the festival (mukaiyama) includes a 6km walk from Hirosaki’s city office to Iwakiyama Shrine as a group. People wear white happi for purity with red hachimaki. They also carry 御幣（おんべ）onbe (staves with plaited paper streamers), large colorful banners, and offerings to the shrine such as apples and mochi.
The second part of the festival (yoiyama) is when they arrive at Iwakiyama Jinja. Groups of people chant サイギ、サイギ (saigi, saigi) while playing 登山囃子（とざんばやし）tozanbayashi in front of the entrance of the shrine. They then proceed to climb to the top of the shrine. The men who carry the bright colored banners must lower themselves to fit underneath the torii and people gather around to watch. The onbe and banners are then placed at the top of the shrine as well.
The last part of this festival is (朔日山) (ついたちやま) tsuitachiyama, when you climb to the summit of Mt. Iwaki, go to 岩木山神社奥宮 (iwakiyama-jinja okumiya), and watch the sunrise from the top of the mountain. Not as many people partake in this part of the festival, but traditionally this was a three day long event.(The reason being that you climb the mountain in the dark only using flash lights and it is about a 4 hour hike up Iwaki). Watching the sunrise on first of August would mark the end of the festival and the beginning of the harvesting season.