The 1861-S Dime is much more scarce than the mintage indicates, as is the case with many of the S-Mint issues of this era. The dearth of collectors on the West coast meant the coins circulated until they wore out or were lost. Thus, a coin from the San Francisco Mint will have a lower survival rate than the a coin of the same date and similar mintage from the Philadelphia Mint. Also, few collectors existed in the San Francisco area, thus fewer high-grade coins were preserved.
Mint State 1861-S Dimes are truly rare and they are seldom nice enough to be called choice. PCGS and NGC have each graded an MS66 example, with very little underlying support. The strike is decent, in general, though the details became mushy as the dies wore out. Die clashing is sometimes seen on the left side of the obverse.
Gerry Fortin has identified two different die varieties for this year. Assuming no more varieties are discovered, this gives an average die life of 86,250 coins.