All historical data can be downloaded in a number of formats from the Audubon CBC Results Page: http://netapp.audubon.org/CBCObservation/. Quickest access is to use the count code, for Cachuma that is CACU.
Here is a link to 2019 data as downloaded from site above: HistoricalResultsByCount [CACU-2020-2020]
Here is a link to all data from 2000-2019: HistoricalResultsByCount [CACU-2000-2020]