Cook pasta according to package directions, drain and rinse with cold water.
In a large bowl combine sour cream, mayonnaise, and ranch dressing mix.
Thinly slice green onions, cut tomatoes into halves or quarters, and chop the lettuce into bite-size pieces.
Add pasta into the bowl with the ranch dressing mixture, stir until pasta is evenly coated.
Add in the green onions, bacon, tomatoes, and lettuce, stir until well incorporated.
Enjoy!