If your parcel abuts property that is maintained by the Bureau of Land Management and there are dead or hazardous trees on their parcel, they can be contacted at the following:

Bureau of Land Management – Mother Lode Field Office
5152 Hillsdale Circle
El Dorado Hills, CA 95762
Phone: (916) 941-3101
http://www.blm.gov/ca/st/en/fo/folsom.html