The BBC website has some historical maps of the Crimean region here.
And some awesome historical maps for sale of the same here.
National Geographic maps here.
Wiki maps here.
I post these to highlight the changing nature of the political boundaries of this region. Including the Crimean Khanate.
Update: Russia is firmly in control in the Crimea, post vote. Moscow has accomplished several goals, one of which is that a clear signal has been given by Russia that political liberalism is not acceptable in Kyiv and, in a pre-emptive fashion, in Moscow. Political liberalism is antithetical to the oligarchs in Russia and any dissent will not be tolerated. Moscow, like Beijing in 1989, will roll out the tanks to quell any unrest. Any attempt at a “colour” revolution or a Tahir Square type movement will not be tolerated. Look for Putin to assert that the Crimea has always been Russian, an appeal to historical rights that the West will have difficulty countering due to their support of Israel. The two most important players have yet to reveal their intentions: Ankara and Beijing. More to come.