Toward or near the source of a river; in the direction opposite to that of the current.

Is upriver towards the ocean?

From Longman Dictionary of Contemporary EnglishRelated topics: Geographyup‧riv‧er /ˌʌpˈrɪvə $ -ər/ adverb away from the sea towards the place where a river begins OPP downriverExamples from the Corpusupriver• Eyes squinted almost shut, he could see less than ten yards upriver.

Which way is up river and down river?

As adverbs the difference between downriver and upriver

is that downriver is travelling in the direction of the river current while upriver is towards the source of a river.