21901 is a Postal Code in Cecil County.
21901 a.k.a. Sidalcea pedata, also called Bird-footed Checkerbloom or Big Bear Checkerbloom, is a rare and endangered perennial herb of California. It blooms between May and July. However, it is an endemic species of California and only occurs in few places in the San Bernardino Mountains, primarily at Bear Valley, Bluff Lake. It grows at 1500–2100 m elevation in moist meadows to open woodlands and the unique pebble plain habitat of the area. Since Big Bear Valley is a resort destination, the birdfoot checkerbloom is threatened by development, vehicles and grazing.