Hydroxypropyl guar (HPG) polymer solutions crosslinked with titanates (Ti) are used in hydraulic fracturing operations. The rheology of these gels evolves from the complex interaction of polymer chemistry, metal ion chemistry, and flow history. Several techniques (steady shear viscosity, dynamic oscillatory shear, Laser Doppler Anemometry, freeze fracture electron microscopy, and NMR were employed to develop a consistent picture of gel rheology. Of primary importance is the imposition of uniform and continuous flow during gelation. Dynamic oscillatory rheological measurements have been used as diagnostic probes of gel structure and are shown to be useful in understanding the effect of chemistry on structure.