Most people who go to Yudanaka/Yamanouchi do so only to see the moneky park. In our case we were there to go snowboarding, but it would have been a mistake not to go to the monkey park of course.
Our last morning in Yudanaka, after a nice breakfast at Ryokan Hakura, Onozawa-San nicely drove us to the park entrance and we got up there bright an early before everyone else, which is good considering how packed with tourists it got by 10:00 when we were about to leave. Thankfully it also opened 10mn early (08;50), giving us a bit of extra time. This also includes a 20-30mn hike on a snowy path from the winter entrance.
The monkeys are of course incredibly cute, and we found plenty of then in the natural onsen in the morning, as a way for them to warm up:
hot vent in the snow
the onsen was full
amazing it can stay in a branch like that