If your rock garden is well drained, then some natives that will work well include Penstemon davidsonii (Davids' penstemon), penstemon procerus (Small flowered Penstemon), allium hookerii (Hooker's Onion), fritillaria lanceolata (Rice root), Armeria maritima (Sea thrift), Lewisia columbiana (Columbia Bitterroot), and Erigeron compositus (Fleabane). All of these plants thrive in our sunny, dry rock garden (along with many non-native rock garden plants).