There is a large sign at the junction of highway 395 and the forest road at the north edge of town in Big Pine. Head east on that road toward the White Mountains as far as you can until a snowgate blocks the way.
The ancient bristlecone pines are believed to be the oldest living things on earth. The forest in which they slowly grow is not accessible by car in winter -- only by snowmobile,snowshoes or cross country skis. The forest actually includes its own aura of antiquity that seems to surround a visitor.