On July 13, 1994, at 1630 Pacific daylight time, a Cessna 172P, N65857, collided with trees during the takeoff climb from the Easton State Airport, Easton, Washington. Visual meteorological conditions prevailed at the time and a visual flight rules flight plan was filed. The airplane was substantially damaged and the flight instructor and private pilot were seriously injured. The flight was departing from Easton and was en route to Renton, Washington. The private pilot reported that the flying club required that he be checked out by a flight instructor for flight over mountainous terrain. Both pilots reported that a full stop landing was made at Easton after practicing an emergency procedure. The airplane was taxied for take off on runway 9 and the private pilot set up for a soft field takeoff with 10 degrees of flaps extended. Both pilots noted that the wind sock was limp. Shortly after takeoff, approximately 300 feet above ground level, the private pilot stated that the airplane was not climbing. The flight instructor took over and stated that he tried to continue the climb-out with a normal pitch and airspeed, however, the airplane was descending. The flight instructor stated that he thought that he extended full flaps, pulled the mixture control and slowed the airplane when it was inevitable that the airplane was going to collide with the 70 foot trees at the northwest side of the runway. Neither pilot recalled that there were any problems with the engine during the take off. The Easton State Airport, is a 2,640 foot turf airstrip that is surrounded by trees and mountainous terrain. The area is subject to up and down drafts. After the airplane was retrieved, an inspection was performed. It was found that the flaps were fully extended. The propeller remained attached to the crankshaft. One blade was bent aft while the other blade remained straight. The crankshaft rotated easily with compression developed in all cylinders. Rocker arm, accessory gear and valve train continuity were established. All spark plugs displayed normal operating signatures. The fuel had been drained from the airplane at the time of the retrieval.