ABSTRACT. Grassland to woodland conversion, also known as woody plant encroachment (WPE), is a global-scale phenomena caused in large part by changes in social processes that affect rural land use patterns. Woody plant encroachment has raised serious concerns for species conservation, provision of ecosystem services, and viability of rural livelihoods and cultures. We examined the social drivers of WPE using a case study of rangelands in a semi-arid watershed. We employed the life course framework to understand how ranchers have made land ranch management decisions in the context of time, culture, and social change. We interviewed landowners whose families have been on the land for at least two generations to examine (1) the social context influencing a landowner's decision to increase or decrease their involvement in ranching over their life span, and (2) the historical events that facilitated constrained involvement. We relate these changes in involvement to the expansion of woody plants. Three major turning points were related to changes in ranching involvement: graduating high school, retirement, and infirmity of a parent. We found that changes in ranching involvement were influenced by large-scale shifts in culture, market regulations, and land values throughout the 20th century. These shifts led to three behavioral changes on the land that facilitated WPE: (1) changes in livestock following the collapse of the sheep and goat market, (2) increased popularity of hunting, and (3) decreased labor availability on the ranch. These observations illustrate the complex social and ecological forces at work throughout the 20th century that have led to land transformation in central Texas.