As the salmon migrate upstream, hungry bears gather and take advantage of their abundance to feed themselves.
Naturopolis: Elevation is a 6-card expansion that adds new blocks that feature bears and salmon. Using the new placement rule, in which higher-altitude blocks must be supported by lower-altitude ones, line up the cascading rivers to ensure that no bear goes hungry.
Set up as normal, then shuffle all 6 Elevation cards into the deck.
The first card placed establishes the lowest altitude on the mountain: all subsequent cards must be placed either on the same row as the starting card OR on a higher row provided they are supported by blocks beneath them.
When an expansion card is drawn, it must be the next card that you play. It may be played on its bear side or its salmon side. These blocks may not be covered later.
At the end of the game, score 2 points for each bear which is at a higher altitude than a salmon on the same river and lose 2 points for each unfed bear. Salmon do not score by themselves. These points are in addition to normal scoring.