Preheat oven to 350 degrees F.
Cut squash in half crosswise around the middle. Use a spoon to scoop out the seeds and stringy stuff in the center of each squash half; discard.
Place squash halves, cut side up, in a greased 15- x 10-inch baking pan; divide butter pieces evenly between each squash halve.
Bake approximately 45 to 60 minutes or until tender when pierced with a fork. Remove from oven.
While the squash is cooking, drain oysters, reserving half of liquid. Place oysters and reserved liquid in a large saucepan; cook over medium heat, stirring occasionally, until oysters just begin to curl. Stir in cream of celery soup, and then spoon the oyster/soup mixture evenly into warm squash halves. Sprinkle with crumbled bacon and minced parsley.
Bake for an additional 5 minutes. Remove from oven and serve.
Makes 8 servings.
* Learn how to How To Shuck Oysters.
Creamed Oysters In Acorn Squash Recipe: https://whatscookingamerica.net/vegetables/acornsquashcreamedoysters.htm