With market goods, demand functions are estimated by examining purchase decisions across markets where the price of the studied good happens to be different. This cannot be done for typical recreation sites because the price rarely changes or there may be no entrance price. As a proxy for price, the travel cost method relies on the cost of travel to the site. The cost of travel to a point of purchase is a compo- nent of the cost of every transaction. For most market goods, this transportation cost is small relative to the price and so is ignored. However, for outdoor recreation, the cost of getting to the site is often sub- stantial and it is a significant component of the overall price. There are consequently two components to the price of a recreation visit: the entrance cost and the travel cost