During a recent 
trip to Japan, I got to visit a colony of snow monkeys which live in a national park in the Nagano area. Their species name is actually the Japanese macaque, and their range is through much of Japan. I was expecting white fur, but they actually have light brown fur; the name comes from their habitat, mountains which are frequently covered in snow.
This colony comes down the mountain each day for free food, then goes back up the mountain for the night. To access the viewing area requires a trek over a dirt path for about a mile. The monkeys roam freely, running literally under your feet, although we were told not to make eye contact with them.
The following information came from signposts within the park —
Males mostly roam alone, eventually leaving their original communities. In the fall, roaming males approach females of another troop in hopes of mating. They have to get by the hostility of males in that troop, but some females will be receptive. In some cases, these males will stay and join the troop. Males will join and leave several troops throughout a lifetime.
Females remain in their original trop their entire lives. Relatives, such as mothers and their children, grandparents and grandchildren, and siblings tend to stay close to each other. One troop will contain multiple families based on kinship shared by females.
The monkeys eat buds from trees, young leaves, flowers, fruits, nuts and seeds. Their diet varies according to each season. They do not return to a den at night; they actually sleep in different places each day. To keep away from predators, they sleep on steep cliffs, rock faces, up a tree or at its base. Some sleep alone, others may huddle together, holding hands or feet. They wake up at the crack of dawn.
And there was a hot spring at the site we visited. It was quite impressive to see them up close.