Mountain rescue dogs (and their handlers) do a great job. Today’s invention is aimed at supporting their efforts.
Every time a mountain walker heads off from base they open a packet containing a scented stick. The manufacturer would make these with carefully controlled amounts of a number of scents, so that they are differentiable by dogs.
One half of the stick is attached to a board or a car parked at base. The other is inserted into a spring-loaded slot in the base of one boot.
During walking, the spring forces the stick into contact with the ground so that tiny, smelly crumbs are shed.
If a walker or mountaineer does not return, a tracker dog can be allowed to smell the half left below and then follow the trail of scented crumbs direct to the missing person.