Arkhangelsk Oblast eventually spread well beyond the Arkhangelsk Region. The Mezen horses, bred in the Mezen River valley, are rather small but suitable for difficult work and easily survive cold winters. The area of current Arkhangelsk Oblast has always been located on the trading routes connecting central Russia to the White Sea, and, in fact, in the 17th century the White Sea was the main sea export route for Russia. The whole course of the Northern Dvina is navigable, as well as the lower course of some of its tributaries, most notably the Vychegda, the Vaga, and the Pinega. The Mezen is
Battle of Bolshie Ozerki of the intervention to involve American forces, though they successfully defended their camp from a Russian attack at Romanovka composed of forces that greatly outnumbered them two months later and inflicted hundreds of casualties during the Suchan Valley Campaign the following month. Allied forces began to withdraw rapidly from northern Russia shortly thereafter. Bolshie Ozerki was a small village situated between the port city of Onega and an important Allied position at Obozerskaya Station, along the Arkhangelsk-Vologda railroad. Because the port of the main Allied base at Arkhangelsk froze every winter, reinforcements had to be brought overland to the front