We have a tree growing in our yard that we didn't plant. I see a tree 2 houses away that looks the same. I ID'd it as a Fremont Cottonwood, BUT pictures of that tree do not match the actual tree. Both plants have something like a "leader" branch, thin, but reaching alone above all the other branches. All other branches are more than 2+ feet below the leader branch. I'm not seeing any trees online that look like that. It also might be a Quaking Aspen, but I don't know. It self planted, apparently, in a moist area where out neighbor's sump pump empties. Can you give me any further advice about identifying this tree? Thank you. P.S. For some reason I can't receive my pictures in gmail. If they come in, I'll forward.
The tree in your yard sure looks like a cottonwood or aspen, but I can't see much detail with the photo. It's difficult to pin down identification of closely related trees like that from the foliage only, we need flowers or seeds. In fact I can't see much at all of the tree in the second photo, in the neighbor's yard because I am unable to zoom in on photos.
The tall leader is not a means of identificaton, that's how many trees put up a central leader. It will eventually start to grow lateral branches. If you think it is becoming unreasonably tall and prone to breakage, you can snip a few inches off the top to suppress the vertical growth and stimulate some branching.