When Tom and his "pirate gang" cross the river to Jackson Island, what does the image of the river symbolize?

The image of the river becomes not only a symbol of "frontier adventure," but also of a turning point in Tom's life. In literature, the endless flow of a river has evolved into an archetype of life itself. Often, crossing the banks of a river can be taken to symbolize a "rite of passage." In applying this definition to Tom's adventure on Jackson Island, we do see that the river is a kind of boundary between reality ­ St. Petersburg, Becky, Aunt Polly, school ­ and Tom's fantasy. Once he has crossed the river, he is no longer a troubled little boy, but a fearless pirate ­ Tom Sawyer, the Black Avenger of the Spanish Main. By running away to Jackson Island, Tom attempts to runaway from reality.