3460 Madison Avenue 3460 Madison Avenue, Boulder, CO is a rental apartment building with 1 floorplan available. It is located in the Baseline Sub neighborhood of Boulder. It has apartment amenities including oven, microwave, air conditioning, in-unit laundry, dishwasher, assigned parking, and hardwood floor. It has building amenities including outdoor space, and storage. Cats and dogs are allowed, making it a pet-friendly building.