Dictionary / Vocabulary / に渡り
にわたり
throughout; over a period of ...; over a span of ...
Also written に亘り
数ヶ月に渡りスウェーデン語を勉強しましたが、まだあまりうまく話すことはできません。
After studying Swedish for several months, I still can't speak it very well.
東京から青森まで車で行って、船に車も乗せて北海道に渡り、北海道を横断して東京に帰りました。
I drove from Tokyo to Aomori, took my car on a ferry to Hokkaido, crossed Hokkaido, then returned to Tokyo.