The terminus of most geomembrane lined facilities, e.g., landfills, surface impoundments and waste piles, is via a small horizontal runout distance and then into a shallow anchor trench. While several analytic models are available for such a design, common practice is usually based upon past experience. However, to better understand the interactions involved, a large scale pullout apparatus was developed where strain gaged geomembranes were evaluated under a set of different normal stresses and exit angles. It was found that low modulus geomembranes (e.g., PVC and VLDPE) develop their full tensile strength in very short distances of 40 to 160 mm, while high modulus geomembranes (e.g., HDPE and CSPE-R) develop their full tensile strength over significantly longer distances of 350 to 750 mm. These tests results offer a choice to the engineer to design on the basis of geomembrane tensile failure or geomembrane slippage. The test is felt to give good insight into the geomembrane's behavior in this particular situation.