Eletronorte also stated they would "resurvey the fall", meaning resurvey the dams on the river. Ferris was called upon to resurvey the Dallas area in 1850. A 1935 resurvey by the Texas State Reclamation Department caused the facility to lose . In 1839, John McDonald was hired to resurvey the line. The Yosemite resurvey documented shifts in the geographic ranges of some mammals. In November 2004, PAASCU conducted a resurvey visit. Grinnell documented 133 species and the resurvey team reported 140 bird species. They might also find or resurvey the corners of the property monumented by prior surveys. The resurvey biologists documented the pinyon mouse on Mount Lyell at elevation 10,500 feet.