Santa Rosa Island is the second largest of the Santa Barbara Channel Islands located about 26 miles off the coast of Santa Barbara. The Island is 15 miles long and 10 miles wide with diverse plant communities including coastal strands, coastal bluffs, grasslands, coastal sage scrub, chaparral, woodlands, pine forest, and riparian and marsh communities.
The island is home to seven plants on the Endangered and Threatened species list, including the Santa Rosa Island Manzanita (Arctostaphylos confertiflora). In 2006, a team of specialists from the NRCS, the CRCD and the Vail Family Ranch surveyed and mapped the occurrence of Santa Rosa Island Manzanita.
The study showed that soils play an important role in the presence and distribution of the plant. Other factors like fire, climate, elevation, precipitation, disease and grazing (elk and deer) may also influence the distribution and abundance of Santa Rosa Island Manzanita.