In East Africa, pastoralist systems are undergoing rapid transformation due to land enclosures, benefit distributions associated with new land uses, shifting social relations, and changing authority and governance structures. We apply a critical analysis of the institutions that mediate access and benefits across a complex mosaic of property relations within Ilkisongo Maasai pastoralist land in southern Kenya. Our analysis elucidates how global and national influences have interacted with shifting dynamics of socio-cultural norms and rules regarding access to create new benefit pathways, cascading patterns of accumulation and social differentiation, and diffuse institutional controls over land.