There are many applications for understanding how material moves on- and off-shore in Texas waters; a major application is oil tarball transport toward the coast. For material to move from off the continental shelf, where it potentially enters the water, to the coastline, where it can cause ecological and human harm, specific processes must occur. In this area, the main forcing mechanism is wind; river discharge and the location of the river plume are also important. Numerical drifters located near the surface of a numerical model of the northwestern Gulf of Mexico are used to study transport processes and the associated underlying physical mechanisms. We find that material is only able to cross the shelf in certain areas during the winter and summer: there is off-shore transport from Texas coastal waters during the winter and from Louisiana during the summer, but there is on-shore transport from deeper water near Texas in both seasons. Once material is on the shelf, it can potentially reach the coastline. Generally, material is more likely to hit the coast in the summer than the winter; however, the details are particular to each location. For example, material that reaches Port Aransas, TX, originates upcoast in the winter, but from offshore and both down and upcoast in the summer. Both are consistent with the dominant seasonal wind patterns. Port Aransas is consistently more likely to hit by material than any other location along the coast in both the winter and summer.