Subterranean formations are subjected to hydraulic fracturing with an aqueous fracturing fluid having guar or a derivative thereof, a borate crosslinking agent and proppant. The fracturing fluid is prepared in a blender and then pumped into the wellbore through an entrance site. The apparent viscosity of the fluid decreases distally from the entrance site such that (i) the apparent viscosity of the fracturing fluid 100 feet from the entrance site is less than 10 percent of the apparent viscosity of the fracturing fluid at the entrance site; (ii) the apparent viscosity of the fracturing fluid 15 minutes after introduction into the entrance site is less than 15% of the apparent viscosity of the fracturing fluid at the entrance site; or (iii) the apparent viscosity of the fracturing fluid is less than 10 cP within 15 minutes after being introduced through the entrance site.