hiking notification form; climbing registration
A form submitted to the police or mountain authorities before a hike, often required for safety and rescue purposes.
登山届を警察に提出してから山に入った。
We entered the mountain after submitting a hiking notification form to the police.
Standard modern spelling; the shorter form without け is widely used in official contexts.
Variant with け; also common, but the shorter form is more frequent in official names.
Compound of 登山 (tozan, 'mountain climbing') and 届 (todoke, 'notification, report').