In deploring the building of Great Seneca Highway across Seneca Creek State Park {Sports, July 5}, Angus Phillips asks a couple of emotion-laden questions:

1) "Can you mitigate 46,000 cars a day through the heart of a sanctuary? Will eagles still come to this place? Will people still come to relax . . . ?"

The answer is sure we can, and the eagles and people are doing it now, despite the fact that this segment of the park is already traversed by I-270, Md. 355, Md. 117 and Riffleford Road -- all heavily traveled except Riffleford. Great Seneca Highway will not increase the number of cars, but will divert them from the other roads.

2) "Will they find better places to put highways than through the middle of a park 15 miles from downtown?"

You can't put the badly needed road where it isn't needed. This park and its sister county park run from Damascus, in the northwest corner of Montgomery County, to the Potomac -- clear across the county. Mr. Phillips' question implies we should cut off access to Germantown, Clarksburg, Poolesville and Frederick.

As a member of the Seneca Creek State Park Advisory Committee, which helped force a reluctant state to finish acquiring the land for the park more than a decade ago, I think the proper course is to protect the environment by making highways compatible with ecological needs. The existing roads have done this, and so will the properly designed Great Seneca Highway.

More constructive than these irrational questions is Mr. Phillips' last question: Will they set aside enough recreational land (so parks won't be closed because of overcrowding)? Twenty years from now, this will be a problem in Montgomery County, and we must begin acquiring more park land now. HARRY M. LEET Gaithersburg