岩内 いわない Iwanai
Iwanai and Kyōwa, Shiribeshi region, Hokkaidō
Ainu spellings: Iwaw-nay, Iwa-nay, Ye-o-nay, Iyaw-nay
Nagata's own entry sets three glosses side by side and closes 「孰が是なるを知らず」; a fourth, iwa-nay, is current besides. Sarashina Genzō calls Iwanai 非常に問題が多い地名. The one point the sources agree on is the association with a smoking sulphur mountain, recorded repeatedly in the Bunka years, when sulphur and alum were carried down by horse and shipped from Iwanai to Osaka.
Location
42.9798, 140.5148 · Coordinates: OpenStreetMap Nominatim, 2026-09-10, on 岩内町. Open in OpenStreetMap
Referents
- settlement The town of Iwanai, the fourth town of Shiribeshi. Iwanai county covers the present Iwanai and Kyōwa; more than half of Iwanai town itself is the steep Raiden range, and much of the Iwanai plain belongs to Kyōwa. At its widest, in 1899, the Iwanai subprefecture also took in Tomari, Kamoenai, Kutchan and Kyōgoku.
- river A river. No stream called the Iwanai River runs in Iwanai today; the Unjōya River, with the Pon-Iwanai as its tributary, is the one the modern readings identify, and the author argues instead for the Horikappu River in Kyōwa.
Analyses
iwaw-nay
イワゥナイ ‘sulphur stream’ received readingProponent: 舊地名解（永田方正が引く） (the older place-name glosses, as cited by Nagata Hōsei)
Nagata reports it as the older gloss: 「舊地名解に「イワウナイ」（Iwau nai）なり硫黄川の義、此山處々に硫黄多きを以て名なづくと」, and adds 「孰が是なるを知らず」 — he does not know which of the three glosses is right. He also says he does not know which river the sulphur one would be. Of the four readings this is the one held most likely.
Evidence
- documents
Bunka-era records tie Iwanai to a smoking sulphur mountain. 東海参譚 (1806): 「イワナイ、硫黄山有て常に煙立。信陽の淺間山よりも甚だし。明礬も爰より出る。」; 未曾有後記 (1806): 「いわない山に煙たつ。（中略）是山硫黄多く産す。年々浪花へ運送す。」; 遠山村垣西蝦夷日誌 (1806): 「巳午の方に当り道法凡四里程に硫黄山有之、前々より製法所相立、当所に馬にて附替候。」
The connection between the name and a sulphur mountain is well documented from the Bunka years on. Which stream carried the name is left open by the earliest source that reports the gloss, and three further readings stand beside this one.
iyaw-nay
イヤウナイ ‘valley where bear meat is dried’ proposed- iyaw ‘hanging bear meat out to dry’
- nay ‘stream, valley’
Proponent: 永田方正 (Nagata Hōsei)
Nagata's entry: 「岩内郡「イヤウナイ」（Iyau nai）熊肉を乾す澤、山中にて熊を殺し其肉を樹皮に掛け乾すを「イヤウ」と云ふ」.
Objections
- The author has not heard of a word iyaw meaning to dry bear meat, and it is not in the dictionaries. — zenibako_trek zenibako_trek…
The first element is not attested in either dictionary consulted here.
ye-o-nay
イェオナイ ‘stream full of pumice’ proposed- ye ‘pumice; pus’
- o ‘have in quantity’
- nay ‘stream’
Proponent: 永田方正 (Nagata Hōsei)
Nagata gives it as 一説: 「一説に「イェオナイ」（Ye-o-nai) 軽石多き川、海濱より岩内川を遡ること凡二里許の處に軽石多く川中に満つ故に名なづくと」. Sarashina Genzō reports the same reading as アエオナイ.
Objections
- There is no dictionary word ye for pumice. Ye is 'pus', so the reading may run: pus of the volcano, that is lava, and the stone lava hardens into, that is pumice. — zenibako_trek zenibako_trek…
The pumice sense of the first element is not attested; reaching it takes a chain of associations the proponent does not spell out.
iwa-nay
イワナイ ‘rocky mountain stream’ proposedProponent: バチェラー博士 (John Batchelor)
The author holds, with a hedge, that Batchelor proposed this first and that Chiri Mashiho followed him. Sarashina Genzō reports it as another current reading: 「イワ・ナイで山あいの川の意味にも解される」.
iwa and nay are dictionary words in the proposed senses and the compound is ordinary. The reading has nothing that ties it to this place in particular, and the article's attribution to Batchelor carries a hedge.
iwaw-nay
イワゥナイ ‘sulphur stream’ proposedProponent: zenibako_trek（小樽銭函地名歴史研究会） (zenibako_trek (Otaru Zenibako Place-Name and History Society))
The author keeps the sulphur reading and moves the river. Iwanai is a name that travelled: Nagata records that the unjōya stood at Omunai but the place was called the Iwanai basho because the Ainu there came from Iwaonai. The same happens at Otarunai, Suttsu and Kushiro, where the trading post takes its name from the people it traded with. The Iwanai Ainu, asked about their river, describe a river rising at Mt. Yōtei, navigable two days by dugout and giving on the road to Yoichi, which fits the Horikappu and not the Unjōya. Horace Capron, coming down the Inaho pass from Yoichi in the early Meiji years, calls the Horikappu the Iwanai River and measures its valley at eight miles wide. The 志利辺津日誌 records the upper tributaries of the Horikappu as イクシユンケイワヲヘツ, where the guide explains that all these streams come down from Mt. Iwao and none of them is clearly the main Iwaonai. Iwanai Ainu lived at the mouth of the Horikappu, where the Horikappu-jinja site and the Horikappu sites have yielded Ainu-period graves, grave goods, a shellmound, a salmon harpoon, lacquerware and Kan'ei coins. They were moved to the present Iwanai harbour, and the name moved with them.
Evidence
- documents
Nagata's Om nai entry states the transfer outright: 「「オムナイ」運上屋と称せずして岩内運上屋と称せし所以は、此場所のアイヌは「イワオナイ」の出身なればなり。」
- topography
The sulphur mountain is Iwaonupuri and the Niseko range around it, about 15 km from Iwanai harbour, which matches the 四里 of the Bunka-era records. Neither the Unjōya nor any other river of the Iwanai plain rises there: Iwaonupuri lies on the far side of the watershed. The Horikappu drains the whole Iwanai plain and its upper tributaries run down from the Niseko range.
- archaeology
The Ainu-period material at Horikappu is substantial, while the Higashiyama site by Iwanai harbour is Jōmon. The Ainu-culture centre of gravity was at Horikappu.
Objections
- The author records against his own case that the upper Horikappu tributaries, the Bira group, do not quite reach Iwaonupuri either; the river that does rise on it is directly below Weisshorn. He answers that the Niseko range as a whole seems to have been called Iwanai-dake: of its peaks only Chisenupuri and the sulphur mountain appear in Edo-period records, Niseko-Annupuri is absent, Nitonupuri was named by Hokkaidō University ski-club members, and the triangulation point on Weisshorn is called 岩尾登. — zenibako_trek zenibako_trek…
- No source states outright that the move from Shiribuka to the present Iwanai took place. The author says so and rests the reading on circumstantial evidence. — zenibako_trek zenibako_trek…
The sulphur reading itself is the received one; what is new is the river it is attached to and the account of the transfer, which rests on circumstantial evidence that the author says is not conclusive.
Attestations
- 岩内 document Genroku era 元禄郷帳
The first appearance of the name. Before it the district is called シリブカ: 正保国絵図 of Shōhō 1 has シリフカヱソ, and 皇圀道度図, ゑぞの絵図 of Kanbun 8 and 松前蝦夷地之図 show シリブカ with no Iwanai. The name Iwanai comes in during the eighteenth century as Japanese control tightens.
zenibako_trek… - イワナイヘツ document Edo period 再航蝦夷日誌
イワナイヘツ 前に志るす川也。又此川、二日路も丸木舟にて上り、山を一日越て、川まヽヨイチへ出る道も有る由也。
A river two days up by dugout, with a further day over the hills to Yoichi. The Unjōya River is neither long enough nor wide enough for that.
zenibako_trek… - イワナイ川 document Edo period 再航蝦夷日誌
運上屋前に川有。イワナイ川と云。此川源シリベツ山より落るよしにて遠し。
Matsuura asks the Iwanai Ainu about the Iwanai of the harbour and is told the river rises at Mt. Shiribetsu, that is Mt. Yōtei. No stream at the harbour reaches it; the Horikappu does bring the mountain into view from its head over the Kutchan pass.
zenibako_trek… - イワヲナイ document Edo period 西蝦夷日誌
イワナイの名義はイワヲナイにて、硫黄澤也。其地南五丁なる川也。此地は本名ヲムナイ也。此所土人昔よりイワナイに住る故、惣名となる也。
The 竹四郎廻浦日記 has the same in shorter form: 「イワナイは此処より南の川の名なるを、当場所の惣名と今はする也。」 The author notes that Omunai and the Iwanai River lie east and west of each other, which makes 'south' odd, and suggests Matsuura may have heard only 'south' from the Ainu and supplied the distance himself.
zenibako_trek… - 岩内川 map Kaei era 西蝦夷地道中見取図
This map, which draws the roads and the houses one by one, places 岩内川 at Horikappu.
zenibako_trek…
Related names
- 運上屋川 うんじょうやがわ — The stream Sarashina Genzō, Yamada Hidezō and Sakakibara Masafumi all identify with Iwanai, on the strength of its tributary the Pon-Iwanai. Its lower course now joins the Notsuka River, though on the older maps it ran to the sea on its own. The author's objection is length: its head does not come near Iwaonupuri, which lies beyond the watershed. He allows that the sulphur road ran up this valley, so that it could be the river by which one went to the sulphur, while noting that the digging was Japanese work and the name Iwanai is older. zenibako_trek…
- 硫黄川 いおうがわ — In Kutchan, rising on Iwaonupuri; the Ainu name is イワオナイ or ペンケイワオナイ, penke-iwaw-nay 'the upstream sulphur stream', against the Nisekoanbetsu River as panke-iwaw-nay, the downstream one. These are the only two rivers rising on Iwaonupuri. Shukusee-henkuru's stockade and house stood on the bank of this one, at the present Asahigaoka park and Daibutsuji behind Kutchan station, which is why the author weighs a Kutchan origin for the name. He sets it aside on chronology: the Wajima family's fortune dates from the Kanpō years of the 1740s, and Iwanai is already in the record in the Genroku years. zenibako_trek…
- 御鉾内 おむない — Where the unjōya stood; the present Bandai in Iwanai town. zenibako_trek…