Formation of Onuma
Onuma is a scenic site set against the backdrop of Mt. Komagatake.
Onuma’s history and allure documented in old literature
The scenic beauty of Onuma stems from the area’s complex arrangement of water and land combined with the majestic figure of Mt. Komagatake in the background. Islets dotting the area’s lakes lie low and do not have any white sand beaches or quays, making the lakes look like flood waters in a bumpy, swampy area. The graceful appearance of Mt. Komagatake is related to the formation of these lakes. Mt. Komagatake simultaneously created Lake Onuma, Lake Konuma and other lakes as mirrors that reflect its own beauty. It is a well-known fact that the lakes in Onuma were formed when rivers were blocked by volcanic mudflows. However, judging from the phenomenon in which trees remain submerged in the same form as several decades ago in some areas under Lake Junsai and Lake Konuma, land subsidence in the late stage of the lakes’ formation can certainly be cited as a factor.
Onuma extends from southwest to northeast and has a gourd-like shape. The large lake in the northeastern area is Lake Onuma, and the small one in the southwestern area is called Lake Konuma. The narrow central area is especially full of beautiful sights.
［Onuma described in old records］
The name of Onuma is derived from “poroto” in the Ainu language. “Poro” means “large” and “to” means a “lake” or a “puddle of water.” That is, Onuma means a large lake. The oldest recorded mention of the area name is in a book entitled Ezo Kiko, which has the passage, “Many cranes inhabited Lake Onuma and Lake Konuma in the Genbun era (1736 – 1740).” A manuscript entitled Tsugaru Kenbunki in 1758 says, “I went about 12 kilometers from here toward the mountain and found a volcano called Uchiura no Goku (Mt. Komagatake). The distance was about eight kilometers. After passing two lakes, there were mountains, swamps and muddy places along the way to an area called Kayabe (today’s Ofuna-cho, Hakodata (formerly Minami Kayabe)), and a great number of cranes were in the wetland.” This shows the area was a habitat or a stopover for cranes.
A book entitled Ezo Junranhikki (1797) says, “I climbed the Kayabe Pass from there. There were trees and open fields along the trail, and I climbed up and down through muddy and dangerous spots. After going down a muddy and slippery trail, I found firm ground and a way to Tomenoyu to the right. Small islets were found here and there in Onuma.
Going along the edge of the lake, I saw deep muddy spots and groves of large trees as well as Mt. Komagatake to the right. A brook ran nearby. I climbed the Konuma Pass and took the narrow trail beside Lake Konuma, which was to the left-hand side. There were muddy spots all over the trail.” Along with the above-mentioned record, this also shows that the Onuma area was a forest wetland.
The oldest recorded mention of the scenic beauty of Onuma is in the magazine Hokuyu Zasshi (1810), which says, “The mountain behind the lake in Onuma is called Yoshinoyama. The name of the mountain reminds me of my hometown. The circumference of the lake is around 12 to 16 kilometers. The lake reflecting the surrounding trees is beautiful…There is a small lake to the left, and a few islets are in the lake. The sight of lush trees and green moss under the rocks in rain is much more beautiful than Kisakata.”
［Onuma depicted by Takeshiro Matsuura］
Takeshiro Matsuura, an explorer at the end of the Edo era and during the Meiji Restoration, changed the name of Ezochi to Hokkaido, and left a wealth of records and diaries on Ezo. He also detailed Onuma in a journal called Ezo Nisshi.
He passed through Onuma in 1845. The journal says, “I went down around two blocks to reach the edge of a lake, where I found a brook and a stone bridge. There was a teahouse over the bridge, that is, this was Lake Onuma. It is said that the circumference of the lake is around 31 kilometers, but the distance of the route along the bay is at least 39 kilometers. In the lake, there are 35 or 36 islets where cairns have been established. It is hard to see the far shore from this shore because of overlapping islets. The Kannon (deity of mercy) found in 33 locations are said to have been built 20 years ago by the master of the teahouse at the edge of the lake, called Tanosuke. Mt. Komagatake can clearly be seen from Tanosuke’s rest area. Visitors buy water-shield, shiitake mushrooms, maitake mushrooms, goby, trout, Japanese littleneck and other local products as gifts.” This part shows that island hopping to visit the Kannon had become popular, meaning that Onuma attracted people as a place of pilgrimage.
Another part says, “I arrived around Onuma. There is a teahouse that sells refreshments to travelers and provides accommodation at sunset. The building stands facing the water and commanding superb views of the area. I hired a boat to go to islets in the lake and visit Kannon. The beauty of the many islets in the lake is, in defiance of Kisakata and Matsushima, beyond description. If this site was along the Tokaido Road and Tosando Road, it would surpass Matsushima.” He detailed Onuma and lavished praised on its scenic beauty.