The Law on Civil Status, pursuant to the new Swiss Constitution of 1874, went into effect only in 1876, following a referendum. It required the creation of civil status districts and uniform procedures throughout Switzerland, and entrusted the Federal Bureau of Statistics with the task of compiling information on the basis of personal declarations of marriages, births and deaths. At the head of each district, the registrar alone had the competency to draw deeds and the authority to celebrate marriages. Detailed information on the history of civil status is available at the website of the Dictionnaire Historique de la Suisse (DHS).
The Civil Registry, regularly kept in the Valais since 1876, can be consulted only under certain conditions, but not by the general public. The registry is under the authority of the Service for Population and Migration, which has possession of these documents. For information, you must contact this service directly (Service de la population et des migrations), or, if your are a Swiss national, the registrar of your township.