Bring a large pot of lightly salted water to a boil; cook rotini at a boil until tender yet firm to the bite, about 8 minutes; drain.
Place bacon in a skillet over med-high heat and cook until evenly brown. Drain and chop.
In a large bowl, mix mayo, ranch dressing mix, garlic powder. Stir in milk until smooth. Place rotini, bacon, tomato and black olives in bowl and toss to coat with dressing. Add salt/pepper, to taste.
Cover and chill at least 1 hour in refrigerator.
Toss with additional milk if salad seems dry.
Nutrition Info Per Serving: Calories 332 Total Fat 28 g Cholesterol 10 mg Sodium 357 mg Potassium 244 mg Total Carbohydrate 15 g Dietary Fiber 2 g Sugars 1 g Protein 5 g