"Bill Haponski" <haponski@seacove.net> was a former S3 and XO of the Blackhorse when he assumed command of the 1/4 Cav in the Spring of 1969.  He wrote: 

Atlas Wedge Day 4 20 March 1969 

Terry Valentine found a John B. Del Valle, SP4 in the 30 April 1969 roster of HHT. Quite certainly he is the trooper who had his leg injured on the 20th. We still have no clue as to what a HHT trooper would have been doing so far south of TF 1-4 Cav location, or who reported the incident.