Joshin'etsukogen National Park
Joshin'etsukogen National Park (上信越高原国立公園 Jōshin'etsu Kōgen Kokuritsu Kōen)  is in Chubu region of Japan whichi is the second largest national park in Japan and consists of mountains and highlands that extend across Gunma, Nagano, and Niigata prefectures.
Flora and fauna
The nearest town of size is Nagano, easily reached by Shinkansen from Tokyo (79 min). From Nagano Station, the Nagaden  Shiga Kogen express bus runs several times a day directly to Shiga Kogen (1:10, ¥1600). All buses go up to Hasuike (蓮池), with some continuing on to Oku-Shiga Kogen (奥滋賀高原) or Shirone Kazan (白根火山).
Alternatively, if you miss the direct bus, take the Nagano Dentetsu train from Nagano to Yudanaka (40 min) and continue by bus to Shiga Kogen (20 min, roughly hourly).
Pensions, Hotels, and Ryokans are available at various ski resorts, which are all somewhat interconnected by lifts if you are skiing and snowboarding