Shirabu, "white cloth", probably received its name from the vast blanket of snow that wraps up the entire valley in winter, as by February, there's often over 2 meters of the stuff. The locals, though, have an even more poetic legend: a hunter discovered a wounded white-flecked eagle and nursed it back to health with the spring's curative water, and then dubbed the spring Shirabuchi Takayu (白斑鷹湯), "White-Flecked Eagle Spring", this being then shortened into today's name.
Legends aside, it's known for a fact that the hot spring here was discovered back in 1312 by a warrior named Sato Muneyoshi, who applied for his feudal lord's permission to open a spring here. Even seven hundred years later, the village remained so small that the original inns didn't even have real names, instead going by "west", "center" and "east" depending on which side of the road they're on!
The nearest major train station is Yonezawa, two hours from Tokyo by Yamagata Shinkansen, while the nearest airport is in Sendai. Yamakō Bus  runs from Yonezawa station to Shirabu, but the service is infrequent: seven-eight buses per day, running roughly every 90 minutes from 8:05 AM to 6:30 PM. The trip takes 40 minutes and costs ¥840. Note that the bus continues a few min onward from Shirabu Onsen to the Tengendai ski lift at Yumoto-ekimae (湯元駅前).
Shirabu is easily covered on foot.
Outside the inns, there's one single noodle shop in the village, which is open sporadically. The ski resort also has a restaurant open in season.
There are three traditional ryokan in Shirabu. Previously all had thatched roofs, but both Higashiya and Nakaya were burned down completely in May 2000 and rebuilt with tiles.
There are three other accommodation options:
Mobile phones work in the village, but coverage gets spotty fast up in the hills near Shin-Takayu.