In chapter 10, Huck dresses as a girl and goes ashore to find out if people are accepting the fact that he is dead.
After his abusive father kidnaps Huck and takes him to the cabin, Huck has to go to extreme measures to get away. He fakes his own death and escapes downriver, where he runs into Jim. Huck gets curious as to whether his stunt worked, so he decides to sneak ashore.
Next morning I said it was getting slow and dull, and I wanted to get a stirring-up some way. I said I reckoned I would slip over the river and find out what was going on. (ch 10)
Jim tells him he needs a disguise, so he dresses as a girl. There he finds out that his ruse has worked, and people really do think that Huck was murdered. However, since Jim disappeared at the same time, they assume it was him. Huck rushes back as soon as he can to warn Jim that they need to leave.