You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Jacksonville,_Florida

Context:
According to the United States Census Bureau, the city has a total area of 874.3 square miles (2,264 km2), making Jacksonville the largest city in land area in the contiguous United States; of this, 86.66% (757.7 sq mi or 1,962 km2) is land and ; 13.34% (116.7 sq mi or 302 km2) is water. Jacksonville surrounds the town of Baldwin. Nassau County lies to the north, Baker County lies to the west, and Clay and St. Johns County lie to the south; the Atlantic Ocean lies to the east, along with the Jacksonville Beaches. The St. Johns River divides the city. The Trout River, a major tributary of the St. Johns River, is located entirely within Jacksonville.

Question:
What river separates Jacksonville?

The St. Johns River