Keystone is located in Pennington County, SD. The population is 397, making Keystone the 10th largest city in Pennington County.
There are 0 public schools in Keystone with an average Homefacts rating of NA. The total crime rate for Keystone is high , and there are 0 registered sex offenders residing in the city. Unemployment in Keystone is low and the median home sales price is $0. Detailed and up-to-date Keystone property reports are available for any property address.
Cities near Keystone include Mount Rushmore, Hill City and Colonial Pine Hills.