In 2013 a team of researchers from the San Diego Natural History Museum completed a five-year survey of the Grinnell Transect , Grinnell 's 1908 study of the flora and fauna of Mount San Jacinto . In 60 surveys across 20 sites , they found the forest to be much denser than in Grinnell 's time , with the loss of three species including a flying squirrel , and an increase in birds that like thick brush , such as the hermit thrush , the brown creeper and the Townsend 's solitaire . The relative lack of leaf litter and decayed ground cover in Grinnell 's time was considered to make the occurrence of hot and lasting fires in the forest impossible . With a much thicker understory in 2013 , the team of researchers were forced by the Mountain Fire to evacuate their camp
Mountain Fire
Mountain Fire
Joseph Grinnell