A method for treating a tar sands formation is disclosed. The method includes providing a drive fluid to a first hydrocarbon containing layer of the formation to mobilize at least some hydrocarbons in the first layer. At least some of the mobilized hydrocarbons are allowed to flow into a second hydrocarbon containing layer of the formation. Heat is provided to the second layer from one or more heaters located in the second layer. At least some hydrocarbons are produced from the second layer of the formation.