The Northernmost Area Where Japanese White Pine Grows

What Is the Goyōmatsu, and Why Does Uzuragawa Matter?

The goyōmatsu (Pinus parviflora) is a graceful evergreen pine prized for centuries in Japanese gardens, ink paintings, and bonsai art. The trees that grow in northern Honshu and Hokkaido are recognized as a distinct variety — kitagoyō, or the "northern five-needle pine" (Pinus parviflora var. pentaphylla). On the main island of Honshu, this tree is common in mountain forests, but its range thins rapidly as one travels north. By the time you reach Hokkaido, only a handful of isolated stands remain, scattered like green islands across the island's vast wilderness.

The Uzuragawa stand, perched on the right-bank ridges of the upper Uzura River in Assabu Town, is the northernmost stable population of goyōmatsu on the Sea of Japan side of Hokkaido. Other surviving stands cluster on the Pacific side — most notably around Mount Apoi in the Hidaka Mountains and the Nipesotsu range of the Eastern Daisetsu — but none on the western coast extend further north than this. For botanists, the site marks the very edge of a species' world.

A Designation Born of Early 20th-Century Science

The story of the site's protection begins with a Hokkaido Imperial University botanist named Misao Tatewaki, who surveyed the Uzura River valley in the late 1920s. He published his findings in the Sapporo Society of Agriculture and Forestry's bulletin in 1927, documenting trees with trunk diameters of 10 to 60 centimeters and heights of 10 to 20 meters at around 600 meters elevation. The following year — on February 7, 1928 — the national government designated the area a Natural Monument under criterion 10, "a remarkable limit of plant distribution."

Originally, the protected area covered an enormous 1,200 hectares. In 1951, sections without significant goyōmatsu growth were released from designation, leaving the present 361.6 hectares. That this designation came just a few years after Japan's Natural Monument system itself was established (in 1919) speaks to how clearly the early conservationists recognized the scientific value of this northern outpost.

Highlights of the Forest

The Uzuragawa zone is not a tidy plantation but a wild, stratified forest where conifers and broadleaves intertwine in ways rarely seen elsewhere in the world.

• A globally rare mixed forest type. The combination of evergreen conifers — kitagoyō, hinoki-asunaro (Thujopsis dolabrata), and Yezo spruce — with deciduous broadleaves like Japanese beech, Mongolian oak, Japanese linden, and harigiri (castor aralia) forms a "needle-broadleaf mixed forest" that is characteristic of Northeast Asia and considered uncommon in a global context.
• Goyōmatsu on the ridgelines. The pines do not dominate the canopy; instead, they cling to rocky ridges and steep slopes on the right bank of the Uzura River, scattered in small groves. From the forest road below, visitors can spot their distinctive silhouettes against the sky.
• A beech-dominated understory. Most of the forest floor is occupied by majestic Japanese beech and the dense bamboo grass known as chishimazasa. In gaps between fallen trees, young goyōmatsu seedlings can sometimes be found, hinting at the forest's slow regeneration.
• An undisturbed watershed. Logging has been prohibited in this catchment since 1908 to protect water sources and prevent erosion, which is one reason the forest's character has survived more than a century of change.

Visiting the Site

It is important to be honest about the experience: the Uzuragawa Natural Limit Zone is not a tourist park with paved trails. The protected stand sits on remote, steep ridges that are difficult and at times dangerous to approach. Most visitors do not enter the designated area itself. Instead, they reach a viewpoint along the forest road that runs through the upper Uzura valley.

To get there, travelers drive National Route 227 from either Hakodate or Esashi, cross the Nakayama Pass (Oshima Nakayama-tōge), and turn onto the forest road leading into the Uzura National Forest. About three kilometers up this road, an interpretive signboard and a stone marker indicate the protected zone. From this spot, you can look up to the steep ridges on the western (right) bank and pick out the silhouettes of kitagoyō pines against the open sky. There is no public transportation; private vehicle is essentially the only option, and the road is best attempted in the green months from late spring through autumn.

The reward of the visit is not a grand vista but a quiet awareness — the sense of standing at the literal edge of a species' range, in a forest that has been allowed simply to be itself for over a century.

What Else to See in Assabu Town

Assabu (厚沢部町) is a small farming and forestry town in the Hiyama region of southwestern Hokkaido, known for its potatoes (especially the May Queen variety) and its surprisingly rich heritage offerings. Combining the goyōmatsu site with other local stops makes for a satisfying day trip.

• Tate Castle Ruins (Matsumae-shi Shiro-ato Tate-jō Ato). The remains of a castle built by the Matsumae clan in 1868, designated a National Historic Site. The earthworks, moat, and well stones are still visible.
• Tsuchihashi Natural Observation Education Forest ("Rec-no-Mori"). Selected as one of "Japan's Top 100 Walking Trails," this accessible forest features a hinoki-asunaro tree estimated to be over 550 years old.
• Mount Taiko Observation Deck. A curious local landmark where the ground is said to make a drum-like sound when stamped on at the summit.
• Uzura Dam Auto Camping Ground (Hachamu-no-Mori). A peaceful campsite on the lake formed by Uzura Dam, ideal for an overnight stay.
• Michi-no-Eki Assabu and Uzura Onsen. A roadside station for local produce and a small countryside hot spring round out the visit.