On September 7, 2013, about 1530 mountain daylight time, a Bell Helicopter 206L-3, N721LL, impacted terrain after the pilot maneuvered to avoid birds during cruise flight near Amistad, New Mexico. The pilot and passenger sustained minor injuries. The helicopter was substantially damaged. The helicopter was registered to and operated by the State of Illinois under the provisions of 14 Code of Federal Regulations Part 91 as a public use flight. Visual meteorological conditions prevailed for the flight, which was not operated on a flight plan. The flight originated from the Dalhart Municipal Airport (DHT), Dalhart, Texas, about 1500. The intended destination was the Albuquerque International Airport (ABQ), Albuquerque, New Mexico.The pilot reported that the helicopter was established in cruise flight on a west-southwest course at 300 feet above ground level prior to the accident. The pilot and passenger were reportedly referencing a radiological monitoring system for proper operation during that timeframe. The pilot stated that about 25 minutes into the flight he observed "multiple large black birds" in the helicopter's flight path and initiated an "immediate hard turn to the right" to avoid them. He subsequently noted an increase in main rotor speed and adjusted accordingly. The pilot rolled out on a reciprocal heading, leveled the helicopter, and began to slow down. He noticed that the descent rate was not decreasing even though appropriate control inputs had been made. The helicopter touched down "hard" and seemed to bounce. The helicopter came to rest about 100 yards from the initial touchdown point. The pilot reported that there were no failures or malfunctions associated with the helicopter prior to the accident. The wind recorded at the departure airport, at 1453, was from 170 degrees at 12 knots, gusting to 21 knots. At 1553, the wind was from 170 degrees at 10 knots, gusting to 21 knots. The pilot reported a clear sky, with an unrestricted visibility of 20 miles and no turbulence.