Live Chat I-90 Community Nearby Traffic Keystone Traffic 2024-09-28 Roadnow Click for Real Time Traffic Weather | Gas | Restaurants | Hotels | Car Repair | Convenience Stores Cities close to Keystone Hill City, SD 18.78 Rapid City, SD 18.83 Custer, SD 20.97 Interstate highway exits close to Keystone Exit 55, i90 27.34 Exit 57, i90 27.92 Exit 58, i90 28.32 Interstate highways close to Keystone i90 map 27.34 i25 map 198.77 i80 map 297.35 State roads close to Keystone US 16A SD map 0.67 SD 244 map 2.20 US 16 SD map 3.98