Mount Sumon - Sumondake

A mountain in the eastern part of Niigata Prefecture, near the border with Fukushima Prefecture. It is located east of Nagaoka City, on the border between Uonuma City and the Shimoda district of Sanjo City. It is the main peak of the Sumomon volcanic group. It is 1,537 meters above sea level. The mountain is made of pyroxene andesite from the Chokai volcanic belt, and is divided into five peaks, including Hakamadake (the main peak), Odake, Maruyama, Takakuwayama, and Kuwadaiyama. It is an aspi-conid volcano with gentle slopes facing the Tochio Basin, Irihirosedani, and Shimoda-go. It has long been a famous mountain for Sumomon mountain worship, and many climbers come here. It is included in the Echigo Sanzan Tadami Quasi-National Park, and a ski downhill competition in early spring is a famous event. Trailheads include Tochibori, Oshirakawa, Yoshigahira, and others.

[Hisao Yamazaki]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

新潟県東部、福島県境付近にある山。長岡(ながおか)市の東方、魚沼市(うおぬまし)、三条市(さんじょうし)下田(しただ)地区の境に位置する。守門火山群の主峰。標高1537メートル。山体は鳥海火山帯(ちょうかいかざんたい)の輝石(きせき)安山岩類からなり、頂上は袴(はかま)岳（主峰）、大岳、丸山、高桑(たかくわ)山、桑代(くわだい)山など5峰に分かれ、栃尾盆地、入広瀬谷、下田郷に緩傾斜面を向けるアスピ・コニーデ型の火山である。古くから守門山岳信仰の名山として登山客が多い。越後三山只見国定公園(えちごさんざんただみこくていこうえん)に含まれ、春先のスキー滑降大会が名物になっている。登山口は栃堀(とちぼり)、大白川(おおしらかわ)、吉ヶ平(よしがひら)などがある。

［山崎久雄］

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