aa2go.com is often helpful. It works well even from a cell phone.
In any case for today and tomorrow, it looks like 44I, which is the remote terminal.
Flight status:
16-Oct AA3107: LAX-LAS
DEPARTED 4:50pm Gate:44I
ARRIVED 6:04pm Gate
8 Bag:3
17-Oct AA3107: LAX-LAS
DEPARTS 4:55pm Gate:44I
ARRIVES 6:10pm Gate
8 Bag:3