hi Roya !
We've been over in Deer Lodge Park for 6 years and we are at a very similar elevation to Cedarpines Park. We have made many improvements through the permitting process with San Bernardino county and they have been amazing and very helpful. There is a local office in Twin Peaks and if you visit, they are happy to answer any questions you might have.
There is a native plant sale at the Heaps Peak Arboretum http://www.heapspeakarboretum.com/
twice a year and we have had great success with elderberry, monkey flower, coffee berry, scarlet bugler and false indigo. We have swales, raised beds with buried logs and quite a few fruit trees that are producing varied results. I think in the mountains greywater is essential as the summers get so hot and dry.
send me an email if you would like communicate.
and have a great day !