Tomasee
lake in Graubünden, Switzerland
Lake Toma (German: Tomasee, Romansh: Lai da Tuma or Lag da Toma) is a lake at the northern face of Piz Badus, above the village of Tschamut in the canton of Grisons (Graubünden), Switzerland. Its surface area is 2.5 ha (6.2 acres).
It is the source of the Anterior Rhine and is deemed to be the official source of the Rhine (the source of the Posterior Rhine is above Hinterrhein, Switzerland, at 46.499°N 9.065°E / 46.499; 9.065 (Source of Hinterrhein)).
It is possible to reach the lake on a path from Oberalp Pass, suitable for most walkers although still a mountain trail.
This brief starts where responsible research should: with the source description of “Tomasee” as lake in Graubünden, Switzerland. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the places & architecture register because the source frames it as lake in Graubünden, Switzerland. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Place names and jurisdictional language are key evidence: both can reveal earlier catalogue descriptions and overlooked record series. The source revision retrieved here is dated Jul 30, 2026. The linked authority identifier is Q690343. Authority coordinates are 46.633, 8.672. 1 of 1 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank.
Modern boundaries and familiar names can conceal earlier jurisdictions or structures that do not align with the present site. The source lead contains qualifying language; that uncertainty should survive quotation, summary and reuse. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Treat names, boundaries and functions as historically changeable. Maps, plans, inventories and administrative records can clarify what the place meant at different dates.
- Historic place names
- Jurisdictional context
- Routes into maps and plans
Contemporary maps, plans, listed-building records, estate papers and the responsible local or national archive.
Three-step research path
- Establish the record: confirm the title “Tomasee”, its source revision and the description used here.
- Expand the search: follow Tomasee primary sources, Tomasee archive and Tomasee research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Tomasee”?
- What physical evidence or contemporary plan supports the description?
- Which authority defined the place, boundary or structure at the relevant date?
Search terms from this dossier
This entry incorporates text from “Tomasee” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.