There is a place on Earth where you can hang out with wild snow monkeys. Not just through bars or over a fence — you can mingle with them as if you've crashed a simian cocktail party. And even when there isn't snow, chilling with snow monkeys is more fun than most hors d'oeuvres or human small talk.

While standing among them, you can see monkeys groom each other graciously, scream at each other angrily and chase each other playfully. Impish infants might bump into your shoe, flash you a tiny scowl and then romp away. And if you're lucky, you may get to see the iconic scene of snow monkeys bathing in a hot spring.

snow monkeysSocial rank dictates many aspects of snow monkey life, including access to resources like a hot spring. (Photo: Shutterstock)

I've wanted to see all that for years, dating back at least to a documentary on snow monkeys I watched with my now-wife when we were in college. We finally went to Japan a few months ago, and although we mostly stayed in Tokyo and Kyoto, we set aside a day in the mountain town of Yamanouchi to see wild snow monkeys.

Those plans began unraveling as soon as we arrived at Jigokudani Monkey Park. A sympathetic ranger met us at the entrance with bad news: "Sorry, no monkeys today." The park is a popular hangout for local monkeys, but they also frequent large swaths of adjacent forest, so there are no guarantees. And on the one day we had dedicated to seeing them, the monkeys apparently had other plans.

Just as we were giving up, however, our luck changed. Details (and photos) are below, but it's worth pausing first for a little context about these monkeys. Whether you're mulling a visit or just wondering about their lives, here are a few facts and first-hand lessons to help illuminate some of the coolest primates on the planet.

snow monkeysSnow monkeys can live up to 30 years, with an average female having 10 babies in her lifetime. (Photo: Russell McLendon)

What are snow monkeys?

Formally known as Japanese macaques (Macaca fuscata), snow monkeys live farther north than any other wild, nonhuman primate. They also like to live in mountainous areas, some of which are snowy up to four months a year. Yet despite their common name and reputation, there's more to these monkeys than just snow.

Wild macaques exist on three of Japan's four main islands (Honshu, Shikoku and Kyushu), plus several smaller ones. They've adapted to an array of habitats across that range, from subtropical to sub-Arctic. Their diverse diet includes insects, fungi and 200 kinds of plants, varying by latitude as well as season. Winter can be especially grim for northern troops, often leaving just bark and buds to pad their fat reserves.

The monkeys' fur is a unique adaptation to cold, growing thicker as habitat temperatures decrease. Along with huddling for warmth, this lets them endure winters down to minus 20 degrees Celsius (minus 4 Fahrenheit).

Snow-monkey society is matrilineal, with females sticking to their birth groups and males moving out to find new homes. Lone males, known as hanare-zaru, spend much of their lives rambling from troop to troop in search of love, unwittingly boosting their species' genetic diversity in the process. A female typically gives birth every other year, having one baby at a time and about 10 in her lifetime.

baby snow monkeysEven young snow monkeys like these seem relatively unfazed by human tourists at Jigokudani. (Photo: Russell McLendon)

Why do they put up with us?

Humans and snow monkeys have developed an odd relationship over the last 60 years. Scientists began studying them closely in the late 1940s, after a wild troop was discovered on Kojima island and lured from the forest with sweet potatoes and wheat. As researchers continued offering handouts over time, the monkeys realized they could forage less often, freeing up more time for creativity.

Feeding any wildlife poses pitfalls, but in this case it also helped scientists study the evolution of snow-monkey culture (PDF). In 1953, for example, they noticed a young female named Imo had begun washing sweet potatoes they gave her — an innovation that slowly spread through the troop, starting with Imo's family. By 1962, about 75 percent of Koshima snow monkeys routinely washed their food.

That wasn't the only breakthrough for Imo, who also went on to pioneer a popular method of sorting wheat from sand. But her species' most famous innovation occurred farther north, in the Shiga Kogen region, where humans began adjusting the temperatures of some hot springs in the 1950s. The idea was to accommodate human bathers, but local monkeys quickly capitalized on the change as well.

snow monkeysBathing in the Jigokudani onsen has become a wintertime routine for many local monkeys. (Photo: Shutterstock)

Where is the monkey spa?

Jigokudani Monkey Park, located near Shiga Kogen within the vast Joshinetsu-Kogen National Park (JKNP), opened in 1964 to let tourists see wild snow monkeys up close. It overlooks Yamanouchi and Shibu Onsen, an ancient resort village that boasts dozens of onsen — a term for Japan's hot springs as well as the spas built around them. Instead of maintaining interspecies onsen, Jigokudani took the unusual step of adding a hot spring specifically for nonhuman guests.

"We built an open-air bath as monkeys' private onsen because it is unfavorable from a hygiene standpoint if monkeys use the same bath [as] humans," the park's website explains." Since then, monkeys inherit the behavior of bathing for generations."

Snow monkeys mainly bathe to warm up in winter, but they sometimes do it in other seasons, too. The warm water doesn't play a role in survival — their thick fur is enough to endure the region's harsh winters — so bathing is apparently a luxury activity motivated by comfort, social connections and cultural tradition.

snow monkeysAfter seeing the monkey on the right paw at the water, the baby repeatedly imitated the motion. (Photo: Russell McLendon)

Onsen isn't everything

As much as monkeys enjoy hot springs, that's not the only reason they come to Jigokudani. Park staff also scatter food to attract them, albeit in a way meant to preserve their wild nature while preventing dependency or aggression. Some places in Japan let tourists feed "wild" monkeys, but that's forbidden at Jigokudani.

"Feeding is not an entertainment show," according to the park's website. "You may know there are facilities which sell feed to anyone who wants to feed monkeys by hand. Monkeys in that place expect to be fed from anybody, so if you do not give them food they would terrorize you or sometimes take your bag away."

Only staff can scatter food at Jigokudani, and they shuffle feeding times so the monkeys can't learn when to expect a meal. They also don't publicly announce the feeding schedule, which means tourists tend to trickle in rather than swarming. The monkeys get nutritious options like barley, soybeans and apples, and since the food is scattered, not dumped, it promotes foraging instead of idle feasting.

Seeing snow monkeys in purely natural conditions must be even better, but that requires time many tourists can't spare, not to mention luck. Wild macaques do inhabit some of Japan's top national parks, including JKNP, Chubu-Sangaku, Hakusan and Nikko, any of which are likely worth a trip even without monkeys. But given limited time, we thought Jigokudani seemed like a good place to start.

Jigokudani Monkey ParkEven if you drive, you'll have to do some light hiking in the woods to reach Jigokudani. (Photo: Russell McLendon)

How to get there

Japan has other monkey parks, like Iwatayama, Choshikei and Takasakiyama, but Jigokudani's bathing monkeys and wild surroundings help it stand apart. Its name means "Hell Valley," a reference to the area's volcanic springs and steep, rugged terrain. Yet while getting there can be tricky, it doesn't need to be hellish.

First, consider a Japan Rail Pass. It's ¥29,000 ($240) for a week, but excluding some local lines, it covers most major trains. Depending on your itinerary, it can be cheaper and easier than individual tickets. It's only for foreign tourists, though, and not available inside Japan, so order it before you go. Other options include a one-day Snow Monkey Pass or a Nagano Snow Resort Pass, but I can't attest to those.

Shibu OnsenThe Yokoyu River flows through Shibu Onsen, a tourist destination since at least the 14th century. (Photo: Russell McLendon)

Yamanouchi is about 200 kilometers (125 miles) northwest of Tokyo, a trip that takes less than three hours by train. The fastest option is a shinkansen (bullet train), which can whisk you from certain Tokyo stations directly to Nagano. From there, it's a 40-minute ride on the Nagano Electric Railway to Yudanaka Station in Yamanouchi. This last leg isn't covered by a JR Pass, but the ¥1,160 ($10) ticket is well worth it. If you can, sit in the train's front-row seats for a panoramic view of the countryside.

Jigokudani is just outside Yamanouchi, and you can get there by vehicle or foot. (The road to the parking lot is a bit narrow for large cars, though, and it's closed in winter.) Walking from the parking lot to the monkey park takes about 15 minutes, while the walk from Kanbayashi Onsen on the Yumichi Natural Trail is about half an hour.

When we arrived at Yudanka in late afternoon, we took a taxi to our hotel and spent the evening walking around the narrow, lantern-lit streets of Shibu Onsen. The ancient maze of spas, shops and restaurants warrants a trip on its own, but while we enjoyed exploring it, we were focused on seeing snow monkeys the next day.

cartoon snow monkeyCartoon snow monkeys are a common sight at shops throughout Shibu Onsen. (Photo: Russell McLendon)

The snow monkeys didn't show up, so planning a single day to see them turned out to be a mistake. But because we stayed in Shibu Onsen for two nights, we had a second chance the next morning before returning to Tokyo.

This time, we had the foresight to call Jigokudani before going. A friendly ranger told us the monkeys were on their way to the park, and the even friendlier hotel staff agreed to hold our luggage after checkout so we could take a quick trip up the mountain. When we got there, we dreaded a repeat of the previous day's letdown, especially after seeing the empty parking lot and few other tourists. But upon reaching the park's entrance, we were suddenly surrounded by monkeys.

snow monkeysA monkey surveys the scene at Jigokudani while other troop members relax along the river. (Photo: Katie McLendon)

How to mingle with monkeys

Even though these macaques are accustomed to people, they have a certain swagger captive monkeys often lack. They carry themselves like wild animals, yet with eerily human mannerisms, making them endlessly entertaining to watch. Although we weren't there during winter, we still got to see a monkey swim in the onsen — a sight that drew excited shrieks from several tourists around us.

We were eventually joined by a few dozen additional human visitors, but the park never felt crowded. The monkeys mostly ignored us, seeming far more interested in each other than in the larger, dorkier primates gawking at them.

snow monkeyEven when it's not cold outside, some monkeys mill around in the onsen for fun. (Photo: Russell McLendon)

Speaking of which, there are some useful rules to keep in mind if you visit Jigokudani. Monkeys may not be known for their decorum, but the park's staff has little patience for anyone else monkeying around.

1. Don't feed the monkeys. Even showing food to them is prohibited.

2. Don't touch. Touching, yelling at or otherwise harassing the monkeys is obviously bad, and not just for their sake. As the Jigokudani website warns, monkeys may bite or "terrorize" humans who bother them. Even babies may seek help from adults if they feel threatened, so keep your hands to yourself. The monkeys generally don't approach tourists, since they aren't fed by strangers, but curious babies sometimes do (one bumped into my foot while I was taking photos of another monkey, for example). If this happens, the park advises stepping away "as soon as possible."

snow monkeyThis bridge overlooking the Jigokudani onsen is a popular hangout for pensive monkeys. (Photo: Katie McLendon)

3. Don't stare. Staring or opening one's mouth is an aggressive display in snow-monkey society, and they hold us to the same rules. Even an absent-minded look or yawn could be misinterpreted, so be careful. Cameras are allowed, but to be safe, I stayed several feet away and only briefly "stared" through the viewfinder.

4. Don't bring pets. This probably won't come up if you're visiting from outside Japan, but it's worth mentioning anyway. I spent about two hours in quiet, amused awe at Jigokudani, but I'm sure my dog's reaction would have been very different.

5. Don't be selfie-ish. A tolerance of cameras doesn't mean there aren't rules for responsible photography. When we were at Jigokudani, we saw a group of tourists being scolded by park staff for taking an up-close selfie with a mother monkey as she nursed a baby. Along the same lines, the park asks visitors to refrain from using selfie sticks (which isn't bad advice for most situations, really).

snow monkeysNot everyone obeys the monkey park's rule against selfie sticks. (Photo: Russell McLendon)

We spent about two hours at Jigokudani before rushing back to our luggage and on to Tokyo for dinner. The diversion to Yamanouchi was a two-day blur within an already-dizzying 10-day trip, but every part was worth it, from the food, the scenery and the sake brewery to the wide variety of hot springs.

And hanging out with wild snow monkeys was as much fun as I'd always assumed, despite the lack of snow. I'm already plotting a return trip, maybe during winter or late spring, when lots of babies are born. Either way, we'll be sure to set aside an extra day or two next time, since snow monkeys can be a little flaky.

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.