In the early autumn of September, the Heilongjiang's climate was mild and its water level moderate, making it the best time of year for navigation. In the past, when the Nurgan Regional Military Commission still existed, the Ming army would seize these finest months to conduct official patrols by boat and transport supplies. Large government vessels carried grain, weapons, and daily necessities down along the great river to the entire middle and lower reaches of the Heilongjiang, becoming the most critical lifeline maintaining the garrisons of Outer Northeast.
At this season, the river was broad and deep, its current neither hurried nor slow, like a silver ribbon winding across the vast northeastern land. And when two broad ribbons came from north to south and met together in the middle reaches of the Heilongjiang, they stirred up the black silt along both banks, revealing somewhat the appearance of a "black river." This was also the place the Kingdom's horse-buying party had reached.
"Blessed by the Main God! I have seen the vast lower reaches of this great river, but I never thought even its upper reaches would be so broad?... Only, in this northeast and northwest, each has a mighty upper great river. Which one, in the end, is the true upper reach of this great river?..."
"Haaha! Ancestral Priest, this winding waterway to the northwest comes from the grassland heartland of the Mongol tribes. It's said to connect with the true 'sacred lake of the God Mountain.' In the inheritance Great Ming left behind, this is the truly longer upper reach of the Huntong River, the 'Buyur Lake' leading into the Mongol heartland! As for this river flowing from the northeast, though it's even broader, it comes, just like the road we took, from the Xing'an Mountains in the northeast.