RedactedNarrative: I, Game Warden was riding double unit on the Colorado River. At approximately 1516 Hours we were dispatched to an accident with injury near the Aquarius Casino. We arrived on scene at 1516 hours. While on scene I ran up the dock where EMS was preparing to transport an injured adult male. EMS informed me that Operator2 would be transported to WARMC medical center. Warden went to WARMC to get a statement from Operator2 on what transpired. It was determined at a later time that Operator2 had sustained a broken left hip that required surgery. Operator2 was transported to UMC Trauma Center. 
  
       It was determined that Operator2 was operating his vessel (V2) upriver. Another vessel (V1) was headed downriver towards Operator2. Due to the inattention of both operators a head on collision occurred. All of the individuals involved in the collision were thrown from their vessels. 
  
  Operator2 was injured during this collision and could not board his PWC. The operator and passenger of V1 both boarded V1 and left the scene of the accident; they did not attempt to help the injured Operator2 in the water. This collision occurred in front of regency dock on the Nevada side of the river. Water Taxi operator witnessed the collision and went to assist Operator2 from the water. Water taxi capt then transported Operator2 to the dock where he could be better assisted. Water taxi capt also confirmed that the operators of V1 made no effort to help the injured Operator2 and proceeded to leave the scene of the accident. 
  
       I proceeded to take written statements from those involved with the overall incident. Operator2 made a verbal statement to Warden due to his medical state. 
  
       After taking photos of V2 I determined the damage to be $150. Warden and I towed V2 to fisherman''s access and helped trailer the vessel. I gave subject my card and information. I informed her that if she had any questions she could call or email me at any time. I also informed her of where her husband was being transported for his medical care. 
  
       Based on my investigation and physical evidence gathered V1 collided with V2 due to a cumulative effect of congested waters and operator inattention by both Operator2 and the unknown operator. 
  
       V2 was heading north under power against the natural river current. V2 attempted to take evasive action to late. Had V2 taken quicker evasive action it would have changed the outcome of the collision. V1 also did not take any evasive action due to the operators'' inattention to his surroundings.