References

Aerial view of Sierra Nevada
http://upload.wikimedia.org/wikipedia/commons/1/1c/Sierra_Nevada_aerial.jpg

Map of Area

http://power.arc.losrios.edu/~reevesl/assignments/images/map_ca.jpg

Historic Railroad Photo
http://upload.wikimedia.org/wikipedia/commons/2/23/Chinese_railroad_workers_sierra_nevada.jpg

Historic Town Photo

http://www.usace.army.mil/About/History/HistoricalVignettes/CivilEngineering/081LoneliestRoad.aspx

Current Mountain Range Photo

http://upload.wikimedia.org/wikipedia/commons/1/1c/Sierra_Nevada_aerial.jpg

Sierra Nevada Natural History
http://books.google.com/books?hl=en&lr=&id=-bSdQh_e8j0C&oi=fnd&pg=PA1&dq=history+of+sierra+nevada&ots=BUZI1JTwVx&sig=vSY_xi7Wi5RrsQyR_3dQ5VhNq-M#v=onepage&q=history%20of%20sierra%20nevada&f=false

Encyclopaedia Britannica: Sierra Nevada - The people and economy
http://www.britannica.com/EBchecked/topic/543431/Sierra-Nevada/39952/Plant-life#toc39954

Air Quality in National Parks: 2008 Annual Performance & Progress Report" Natural Resource Report NPS/NRPC/ARD/NRR—2009/151 by the National Park Service - U.S. Department of the Interior http://www.nps.gov/yose/naturescience/upload/AQ.Trends.Parks.2008.pdf

McKelvey, Kevin, and James Johnston. "Historical Perspectives on Forests of the Sierra Nevada and

the Transverse Ranges of Southern Califronia: Forest Conditions at the Turn of the Century." Trans.

Array USDA Forest Service Gen. Tech. Rep. PSW-GTR-133. 1992. 225-246. Print.

Source one 

Peter B. Moyle and Paul J. Randall, Evaluating the Biotic Integrity of Watersheds in the Sierra Nevada, California. Wiley for Society for Conservation Biology. Conservation Biology, Vol. 12, No. 6 (Dec., 1998), pp. 1318-1326.
Source two

Ricardo Cisneros, Andrzej Bytnerowicz, Donald Schweizer, Sharon Zhong, Samuel Traina, Deborah H. Bennett, Ozone, nitric acid, and ammonia air pollution is unhealthy for people and ecosystems in southern Sierra Nevada, California, Environmental Pollution, Volume 158, Issue 10, October 2010, Pages 3261-3271, ISSN 0269-7491, http://dx.doi.org/10.1016/j.envpol.2010.07.025.
(http://www.sciencedirect.com/science/article/pii/S0269749110003179)
Source three

[http://www.sierraclub.org/environmentallaw/lawsuits/0127.aspx]

[http://earthjustice.org/news/press/2004/bush-administration-to-increase-logging-in-sierra-nevada-national-forests]