The Kamchatka or Central (Sredinny) Range forms the spine of the peninsula. Along the southeast coast runs the Eastern Range (Vostochny). Between these lies the central valley. The Kamchatka River rises northwest of Avacha and flows north down the central valley, turning east near Klyuchi to enter the Pacific south of Kamchatsky Point at Ust-Kamchatsk. In the nineteenth century, a trail led west from near Klychi over the mountains to the Tegil river and town, which was the main trading post on the west coast. North of Tegil is Koryak Okrug. South of the Tegil is the Icha River. Just south of the headwaters of the Kamchatka, the Bistraya River curves southwest to enter the Sea of Okhotsk at Bolsheretsk, which once served as a port connecting the peninsula to Okhotsk. South of the Bistraya flows the Golygina River.