With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: More than 500 lakes and ponds are located within North Cascades National Park. Many of these are devoid of fish, a phenomenon which is quite rare, even in steep terrain where fish may not be able to access high altitude waterways. Around 240 of these lakes exist in the higher elevations and stocking of some of these lakes with fish has been ongoing since the late 19th century. In 2008 an Environmental Impact Statement was produced that examined whether these lakes should continue to be stocked, and if so, what the impact would be on native species such as salamanders and other aquatic life.
text_B: Would a fisherman in the Rocky Mountains expect to be able to catch an uncommon species of whitefish in a high-altitude lake?
YES.