Most of the Little Buffalo is private property, but you can put in at the bridge in Jasper and take out at a place called String town Bridge. It's not a short float, but its very doable in one day. You could also put in at String town bridge and float all the way to the confluence of the Buffalo then float down to Hasty and take out. I'm pretty sure this float is quite a bit shorter. Maybe half a day. Its been a good while since I've done it. I could be wrong.
To get down to String Town bridge coming from Pruitt bridge heading south towards Jasper... Once you get towards the top of that steep winding hill after you cross the Pruitt bridge, you will see a truck pull off on your right and two dirt roads forking off to your left. Take the dirt road that goes downhill on the right, co road 46 all the way to the bridge.