I saw this tree in the Fish Creek area of the San Gorgonio Wilderness at around 7500' of elevation. I'm not exactly sure what it is. Click to enlarge.
Can anyone help me make a positive ID? I believe it's in the same family as cottonwoods and aspens (Salicaceae family). It's from just up from Aspen Grove, but it's leaves are different than the leaves of the aspens in the grove which are smaller and more circular.
Kevin on the San Gorgonio Wilderness Assoc. board identified my mystery tree as Black Cottonwood (Populus trichocarpa). A big thank you to Kevin. Inquiring minds want to know you know.