Scrounged wood ID?

My first wood id thread, this is rather exciting haha

Anyways, I brought a good bit of this wood home from a house up the road where Ive been working on a red oak (http://www.hearth.com/talk/threads/scrounge-from-today-and-last-weekend.105580/), the guy said I could take this as well. I thought it was locust but thought Id let you guys give your opinions as im a novice

Here it is:

Looks like ash

Got any photos of some fine branch tips?

No branches it was just big pieces of trunk on the ground

Not really familiar with Cottonwood, but could this be some? Bark looks similar...

It was surprisingly light. I could easily rotate/roll/maneuver 6ish foot sections of it to cut

cottonwood!

Well ya win some ya lose some I guess haha