Cindy's Spinach Salad

Ingredients

• 1 cup olive oil
• 12 cup cider vinegar
• 12 cup sugar
• 14 teaspoon fresh pepper
• 1 medium onion, finely chopped
• 1 teaspoon paprika
• 1 teaspoon salt
• 12 teaspoon dry mustard
• 12 teaspoon celery salt
• 3 bunches spinach
• 24 fresh mushrooms, sliced
• 1 lb bacon, fried, drained and crumbled
• 2 (11 ounce) cans mandarin oranges, drained
• 2 avocados, chopped