I need a 1 gallon propane tank that will work with a standard gas grill in Denver, CO or surrounding, help!!!!

A one gallon tank is usually referred to as a 5 pound tank.These tanks can be purchased at your local Propane distributor.It will be much more expensive than a standard 20 pound tank because so few are sold compared to the millions of 20 pound tanks that are sold.You many want to buy two of these tanks because on cooler days these little tanks may not be able to vaporize the volume of gas that the grill requires and you may need to change tanks to let one heat up again.This problem will be worse as the tank gets closer to empty.They frost over and then the liguid Propane will not change to gas fast enough.