The western slopes of Sapporo-dake (札幌岳) are marked by their long, graceful ridgelines, while the north face is clearly visible from the southern suburbs of Sapporo City. The name of the mountain probably comes from the old Ainu name for the Toyohira River (豊平川), the headwaters of which river are to be found here. Before the Meiji-era colonization of Hokkaido by the Japanese, the Toyohira River was called sat-poro-pet, meaning 'big, dry river.'
As the mountain sits quite close to the popular onsen town of Jozankei (定山渓) and the similarly popular Hoheikyo Onsen (豊平峡温泉), and as the mountain can be climbed as a day trip from Sapporo, it's one of the more popular hikes on the island. Furthermore, the trails passes the quaint Hiyamizu-goya mountain hut (冷水小屋), lying alongside the Hiyamizu-sawa (冷水沢), making this an excellent overnight hike if you're interested. The traverse from the summit to nearby Soranuma-dake (空沼岳) in the east is an easy hike in summer and a lovely ski-touring trip in winter.
From National Route 230 (国道230号線), heading in towards Hoheikyo Onsen, you'll find the trailhead just before the Hiyamizu Tunnel (冷水トンネル).
The first half of the hike consists of a refreshing walk alongside the Hiyamizu-sawa. In early spring, Anemone flaccida (ニリンソウ) and Trillium tschonoskii (ミヤマエンレイソウ) bloom along here. At 750 meters in elevation you'll arrive at Taifuu-kogen (台風高原), a reclaimed forest of Sakhalin fir (Abies sachalinensis, トドマツ) and Erman's birch (Betula ermanii, ダケカンバ). In 1954 the typhoon Toya- maru (洞爺丸) knocked down the greater part of the forest here; the current forest along this plateau grew from the deadfall. You'll ford the stream a number of times through here before arriving at Hiyamizu-goya. Though the hut here stands two stories tall it's built from local lumber and blends in with the surrounding forest. The mountains around Jozankei tend to be dotted with winter-ready huts like this, which make great bases of operation for wintertime ski tours.
From Hiyamizu-goya onwards the trail starts to get quite steep. You'll pass through first a conifer forest and then a grove of twisted Erman's birch. Winters bring a lot of snow in these mountains, so even in mid-May you'll probably see a good deal of snow on the lee sides of the ridgelines. Across the deep valley of Hoheikyo, you should be able to see the graceful form of Muineshiri-yama (無意根 尻山).
From the summit of Sapporo-dake, the you'll find a view out over Jozankei and the city of Sapporo like nowhere else. Among the old dwarf stone pine (Pinus pumila, ハイマツ)on the summit, you'll encounter a peace you wouldn't think could be found within the Sapporo city limits. Regrettably, however, most of the high-altitude flora that used to grace the mountaintop has been dug up and transplanted elsewhere.
The trail down is the same one you took up.
That all being said, there are a number of small, pleasant mountain huts around here; and walks along the streams and ridgelines of the area, especially in late spring or at the changing of the leaves in the fall, can make for incredible weekend treks.
If you're heading to Soranuma-dake in the east, it's worth taking your time and stopping at a mountain hut along the way. Alternately, you can make a traverse to Toyotaki Falls (豊滝) by taking the trail at the junction east of the summit.
Up until Golden Week the trail should be trod only by experienced hikers. From May onwards you should see Sargent's cherry trees (Prunus sargentii, エゾヤマザクラ) blooming around the foot of the mountain; as the snow melts and feeds the streams, spring flowers should crop up along there as well. After June is the best time to see the greenery as the snow will be almost completely gone. The fall leaves are best in the first half of October.