spice wrote:
Rafts are probably easier & quicker to build, requiring much smaller trees.
They would require cordage. Cordage is quickly & easily made with the fibers extracted from the stems of many kinds of plants. I watched a video of an anthropologist demonstrating just how quick & easy it was to make cordage. In essence, the process was almost identical to the process of making wool yarn, except there was no spindle. He twisted the fibers by rolling them against his leg, adding fibers to lengthen the cord as he was making it. He made a usable amount of cord in mere minutes. Then he demonstrated how to ply the cordage into thicker cordage using no tools at all, just his hands.
Cordage might have been used for snares. Then you have bags and lightweight clothing.
But you have to know your knots.
I don know how this might be definitively show by the archaeological record.
Small game bones with fractures?
Clusters of things carried?
Hand axe, fire, cordage...
On the other hand, people were probably already using fallen logs to ford rivers.
Then you simply dig down into them with your existing axe and fire to make a dugout.
As more sites are found, excavated, and recorded,
Someday in the future we'll have some answers.
Until then, it will simply be an intellectual exercise in speculation.