The answer to this can be found in Chapter 11. In that chapter, Huck dresses up like a girl and goes into town. He ends up in the home of Mrs. Loftus and gets news from her.
What he finds out is that people really do believe that he (Huck) is dead. They at first thought that his dad killed him, but then they started to believe that Jim had done it because he ran away the same night Huck was "killed."
There is now a reward of $300 for Jim and $200 for Huck's dad.
The nigger run off the very night Huck Finn was
killed. So there's a reward out for him -- three hundred dollars. And there's a reward out for old Finn,too -- two hundred dollars.
In Ch.11 Huck disguised as a girl "Sarah Williams" from Hookerville visits Mrs. Loftus and discovers that initially Huck's father Pap was suspected of murdering Huck and later the people suspected Jim of murdering Huck. Since Pap left the town after squandering all the money that the judge had given him to find Jim there's a reward of 200 dollars on him. People suspect Jim because he ran away the same day that Huck was believed to have been killed. Now there's a reward of 300 dollars on Jim.
In Mark Twain's book "The Adventures of Huckleberry Finn" Jim and Huck run away. People believe that Jim is responsible for Huck's death. No one really knows what has happened to Huck but they believe he was killed. Since Jim left the same night they assume it was him. A price is placed on Jim's head with a reward of $300.
"So there's a reward out for him-three hundred dollars."(53)
The people also think that Huck's dad may be responsible for Huck's death. Huck's dad cries and gets money from Judge Thatcher so he can go looking for Huck. However, he takes the money and gets drunk and leaves town. There is now a price of $200. on his head as well.