Understanding "雪の色はそこまで行かぬうちに"

Question

Consider

もうそんな寒さかと島村は外を眺めると、鉄道の官舎らしいバラックが山裾に寒々と 散らばっているだけで、 雪の色はそこまで行かぬうちに闇に呑まれていた。

which apparently means

When Shimamura gazed outside, thinking it had already gotten cold, railroad residence-like barracks were desolately dispersed at the foot of the mountains, and before the snow hues could reach that far, the barracks were swallowed by darkness.

I'm having trouble parsing "雪の色はそこまで行かぬうちに". What does うち mean in this context, and how is it being used with the 連体形 before it to form the meaning of "before the snow hues could reach that far"?

Answer 1

雪の色はそこまで行かぬうちに has the same structure as 花子が学校に着かないうちに = before Hanako reaches the school. Thus it means before the color of snow goes that far.

I think it is a matter of interpretation, but the part resonates with the beginning

国境の長いトンネルを抜けると雪国であった。夜の底が白くなった。

So it is late in the evening, and the scenery Shimamura is seeing is colored white at bottom. He sees barracks in the distance, but the color of snow is already gone around/before there. (This may sound not logical, but I don't think it's surprising in Kawabata's writings.)

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The translator takes the subject of '闇に吞まれていた' as the barracks. I'd say it is possible, but then it would be definitely more natural to say 雪の色がそこまで行かぬうちに.