Joseph Grinnell and Joseph Dixon, Natural History of the Ground Squirrels of California…
“ Metropolis of "digger" squirrels in a grain field 36 Fig. 16. Badly infested hillside 41 Fig. 17. Map showing distribution of the "digger" squirrels 46 Fig. 18. Map showing distribution of the Oregon, Belding, Stephens Soft-haired and the Round-tailed Ground Squirrels 61 Fig. 19. Plot of excavated nesting burrow of Oregon Ground Squirrel 64 Fig. 20. Life photographs of Oregon, Belding and Sierra Golden-mantled Ground Squirrels 69 Fig. 21. Plot of excavated burrow of female Belding Ground Squirrel 71 Fig. 22. ”
