Here's a short story:

The Ohio River, which streams westward from Pittsburgh, Pennsylvania, to Cairo, Illinois, is the largest tributary, by volume, of the Mississippi River in the United States. At the confluence, the Ohio is considerably bigger than the Mississippi (Ohio at Cairo: 281,500 cu ft/s (7,960 m/s); Mississippi at Thebes: 208,200 cu ft/s (5,897 m/s)) and, thus, is hydrologically the main stream of the whole river system. 

The river flows through or along the border of six states, and its drainage basin includes parts of 15 states. Through its largest tributary, the Tennessee River, the basin includes many of the states of the southeastern U.S. It is the source of drinking water for three million people. 

It is named in Iroquoian or ,  "Good River" or and "Spelewathiipi". The river had great significance in the history of the Native Americans, as numerous civilizations formed along its valley. For thousands of years, Native Americans used the river as a major transportation and trading route. Its waters connected communities. In the five centuries before European conquest, the Mississippian culture built numerous regional chiefdoms and major earthwork mounds in the Ohio Valley, such as Angel Mounds near Evansville, Indiana, as well as in the Mississippi Valley and the Southeast. The Osage, Omaha, Ponca and Kaw lived in the Ohio Valley, but under pressure from the Iroquois to the northeast, migrated west of the Mississippi River to Missouri, Arkansas and Oklahoma in the 17th century. (End of story)

Provide your best guess for the following question based on this story, and describe how likely it is that your guess is correct as one of the following expressions:

Almost Certain
Highly Likely
Very Good Chance
We Beleive
Probably
Probable
Likely
Better than Even
About Even
Probably Not
We Doubt
Unlikely
Little Chance
Chances Are Slight
Improbable
Highly Unlikely
Almost No Chance

Give ONLY the guess and your confidence, no other words or explanation. For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>
Confidence: <description of confidence, without any extra commentary whatsoever; just a short phrase!>

Here are a few examples of questions and answers:

Question: How many state doe the Ohio River go through or by?
Guess: six
Confidence: <appropriate level of confidence in this guess>

Question: How many are included in it's drainage basin?
Guess: 15
Confidence: <appropriate level of confidence in this guess>

Question: How many people use it for drinking water?
Guess: three million
Confidence: <appropriate level of confidence in this guess>

Question: What is one of its tributaries?
Guess: Tennessee River
Confidence: <appropriate level of confidence in this guess>

Question: Where does that rank in size among all its tributaries?
Guess: The largest
Confidence: <appropriate level of confidence in this guess>

Question: What river is the Ohio River a tributary of?
Guess: Mississippi
Confidence: <appropriate level of confidence in this guess>

Question: How is that measured?
Guess: cu ft/s
Confidence: <appropriate level of confidence in this guess>

Question: Which way does it flow?
Guess: westward
Confidence: <appropriate level of confidence in this guess>

Question: Beginning where?
Guess: Pittsburgh
Confidence: <appropriate level of confidence in this guess>

Question: Where is that?
Guess: Pennsylvania
Confidence: <appropriate level of confidence in this guess>

Question: Where does it end up?
Guess: Cairo
Confidence: <appropriate level of confidence in this guess>

Question: Is that that in Egypt?
Guess: No
Confidence: <appropriate level of confidence in this guess>

Question: Where?
Guess: Illinois
Confidence: <appropriate level of confidence in this guess>

Question: For what group is the river a big part of history?
Guess: Native Americans,
Confidence: <appropriate level of confidence in this guess>

Question: What did they make along it?
Guess: civilizations
Confidence: <appropriate level of confidence in this guess>

Question: What did it connect?
Guess: communities
Confidence: <appropriate level of confidence in this guess>

Now answer the following question in the same format.

Question: Did they use it for anything?

yes