A Montgomery county physician reported an unexpected and damaging encounter in upper Northwest Washington last night with a traffic hazard almost unknown on the streets of the District of Columbia. Dr. Thomas E. Kasper said that his car collided with a large deer.

After the collision, which Kasper said occurred about 7:30 p.m. as his car was eastbound on Dalecarlia Parkway, the animal fell, apparently fatally injured, at the side of the road.

Kasper said he was unable to stop because of traffic. Another man who was driving on the parkway shortly after the accident said that he saw a fallen buck with six points on its antlers.

The parkway is a tree-lined artery that runs through an area east of the Dalecarlia reservoir, near the border of the District and Montgomery County.

An employe of the city's animal control unit said that several sightings of deer have been reported there in the past month.

Police found signs that an animal had been injured but could not immediately locate it.

Kasper, who described himself as surprised by the encounter, said the deer had come across the road from his right as he was driving from Sibley Hospital toward Westmoreland Circle.

The collision damaged his car but left him unharmed, he said.