What are the demographic and economic effects of gold and oil in Alaska?

Demographics - In two words, "white people". Before the discovery of gold (and later, oil), it was all native Alaskans and the occasional whaler or fur trapper. The discovery of the gold in the Klondike in 1897 brought 40,000 people to Alaska. The 1890 census counted 32,000 people in Alaska, only 4,000 of which were white. In 1900, there were 68,000 people, 30,000 of which were white. Within a ten year period, the population of the state doubled and the number of white people increased by over 7x.

http://laborstats.alaska.gov/census/hist.htm

Economics - totally changed the economy from fishing and hunting to mining and natural resources. As one obvious and long lasting benefit, Alaska continues to have no income tax (due to oil and mining royalties), but rather pays it's citizens to live there. The Alaska Permanent Fund Dividend is typically around $1,000/yr paid to every man, woman and child in Alaska. The permanent fund was created entirely from oil money. Alaska is the only state in the union that pays residents to live there, instead of the other way 'round.

http://en.wikipedia.org/wiki/Alaska_Permanent_Fund