Finding a suitable winter den can determine whether a bear survives months of cold, deep snow, and food scarcity. For pregnant females and mothers with cubs, the choice matters even more, since the ...

High water forced us off the planned route and into a section of cave that no one had ever explored before, and the second we squeezed into it we knew we’d crossed into something different. The walls ...

The footage shows a cave that shrinks with every turn — entrances you can barely slide into, passages where you must exhale completely just to move an inch, and ceilings that press your back flat ...