Natural Grocers by Vitamin Cottage, a mid-west retailer of natural and organic groceries and dietary supplements, filed on Monday with the SEC to raise up to $115 million in an initial public offering. The Lakewood, CO-based company, which was founded in 1955 and booked $297 million in sales for the 12 months ended March 31, 2012, plans to list on the NYSE under the symbol NGVC. Suntrust Robinson Humphrey and Piper Jaffray are the joint bookrunners on the deal. No pricing terms were disclosed.