53 
Crossosoma 34(2), Fall-Winter 2008 
That locality is too vague to attribute the specimen to known occurrences, such as 
nearby Cyrus Canyon, or an otherwise undocumented locality that may have been 
inundated by Lake Isabella, or eliminated by surrounding land development. The 
occurrence is reported as EO 8 in the CNDDB (2009). 
Newly documented occurrences 
In 2008, two previously unknown Mimulus shevockii occurrences were 
documented ( Fraga 1990 & Fraga 1992; to be deposited at RSA). These 
occurrences extend the range of M. shevockii seven miles to the south. Both are 
on private property adjacent to BLM land managed by the Ridgecrest Office (Fig. 
2) . Cattle grazing and off road vehicle use are threats to these newly documented 
occurrences. There are several areas that have been identified as potential habitat 
in the Kelso Valley region, and it is likely that additional populations are awaiting 
detection (Fraga 2007). 
Threats 
Mimulus shevockii occurrences are threatened or potentially threatened by several 
factors. These include land use conversions for agriculture and development of 
homes; cattle grazing, off road vehicle use, presence and abundance of invasive 
exotic plant species, and road maintenance. At least one of these threats has been 
documented at all known M shevockii occurrences. One occurrence documented 
by Bangsberg in 1932 (Bangsburg s.n., 17 Apr 1932), may have been extirpated 
due to the creation of Lake Isabella in 1953. 
CONSERVATION RECOMMENDATIONS 
Recommendations outlined in the conservation plan (Fraga 2007) include: 1) 
Maintain all existing occurrences. 2) Preserve existing habitat of M. shevockii. 
3) Limit impacts from disturbance (e.g., residential development, OHV use, and 
cattle grazing). 4) Establish an ex-situ maternal line seed collection(s). 5) Survey 
additional areas with potential habitat for additional occurrences. 6) Assess 
the genetic diversity of the species to identify meta-population dynamics. 7) 
Identify any specific research needs at each occurrence. Additional conservation 
recommendations are provided below. 
Mimulus shevockii is vulnerable to local extirpation due to several underlying 
factors. Abundance of individual plants and areas and numbers of sites they 
occupy vary widely from year to year, presumably due to fluctuations in rainfall 
and other climatic variables. Thus, it is difficult to assess population size and 
