What does "along a narrow arm of the river that snaked its way into the forest" mean in this context?

Question

I would like to know what "along a narrow arm of the river that snaked its way into the forest" means in the following sentences:

On our last evening the comrade leader made a speech, thanking us for our hard work. Then he ordered us down to the river. We walked in little groups, unsure what would happen, filled with excitement tinged with dread. But what we came upon were dozens of little boats flopping in the water. We got in, six to a boat, me with Karolina and Beata and the boys from my hut, and we rowed down the river, not towards our spot, but in the other direction, where the forests began. We formed a line of boats with Belka at the head. We saw the sun set far behind the fields we’d so carefully emptied that month, and along a narrow arm of the river that snaked its way into the forest. Tall pine trees began surrounding us, fragrant, solemn and seemingly infinite. It was cooler there, and utterly dark, and soon the only light came from the faint moon above us, barely visible in-between the canyon of the treetops, and the distant light of Belka’s torch in front. We heard the sound of light paws on the forest floor, and the cracking of branches. An owl hooted.

• Tomasz Jedrowski, Swimming in the Dark, Chapter 2

In this novel which is set in the 1980's in Poland under the socialist regime, where homosexuality was socially unacceptable, the protagonist Ludwik (a university graduate) left Poland in 1981 to live in the United States of America. And he remembers what it was like back then in Poland, where he went to the agricultural camp (which was mandatory for college graduation). On the last night of the camp, the comrade leader held a party for students who worked hard on the fields for the past month.

In this part, I wonder whether it would be right to understand the structure of the sentence to be "We saw the sun set (1) far behind the fields we’d so carefully emptied that month, and [we saw the sun set] (2) along a narrow arm of the river that snaked its way into the forest. In short, I wonder whether it would be alright to see that the setting sun was the background of the fields and the river.

Also, I would like to ask you whether "along" implies that the river snaked along (across?) the fields too before coming into the forest.

Lastly, I would like to ask you whether "snaked its way into" means that the river was curved, and flowed in a hard, not-so-smooth manner to come into the forest.

I am an English learner from South Korea, so thank you for your patience in advance as I may not know obvious things. I would very much appreciate your help. :)

Answer 1

The arm of a river is a branch of a river that flows into the main stream. For example, one may describe the Bukhan River as a arm of the Han River in Korea. (The geographical term is tributary or affluent).

In Jedrowski's novel, the "narrow arm of the river" is a tributary that isn't wide at all.

It "snaked its way" means that it didn't follow a direct course but has many curves, just like a meander. As the river flows in the direction of the forest and then into the forest, it follows a path that is similar to that of the movements of a snake.