On a hike in Yellowstone National Park this summer, I came upon the following scene. 

If you ever wondered where bears sleep, here's at least one answer: on a log in the forest.  I was able to take this picture from across a river.

On subsequent visits to this remote area, I was fortunate enough to observe this black bear sow and her two cubs on multiple occasions.  Just for fun, I nicknamed her Maria and my wife named the two cubs Bread and Butter.  While I observed her for many hours, I saw them graze, climb trees, swim across the river and she even nursed the two cubs in front of me!

An amazing experience made possible by no car traffic being nearby or even other visitors for that matter.  The mom was very trusting towards me and I kept my distance as required, so as to not interfere with her living space or create a perceived threat for her two adorable cubs.

Even though big telephoto lenses are a pain to carry around; especially on hikes where you don't get to see any wildlife 90% of the time; sometimes it pays off ...