(Gresham, OR)  --  Gresham police are trying to identify the driver who critically injured a 16-year-old girl in a hit-and-run crash.  Aleyda Perez was walking home from a friend's house late Friday night and was hit while crossing at the intersection of 199th and Southeast Stark Street in Gresham.  Police say Perez was in a marked, lighted crosswalk at the time.  There's no information on the vehicle's description.  Anyone with helpful information is asked to call 503-618-2719.