I was looking up the boundaries of Wonder Valley at the San Bernardino County LAFCO site and found this:
San Bernardino County Fire Protection District - Service Zone FP-4 (Wonder Valley)
Report Created: 1/22/2018
"The San Bernardino County Fire Protection District reorganized in July 2008 and created the South Desert Regional Service Zone. The South Desert Regional Service Zone is a component unit of the San Bernardino County Fire Protection District, in which the County Board of Supervisors is the board of directors of the district. Within the South Desert Regional Service Zone, Service Zone FP-4 Wonder Valley special tax was originally authorized by the Board of Supervisors in August 1972 (originally under CSA 70 M Zone FP-4). Service Zone FP-4 provides fire protection services to the community of Wonder Valley. These services are funded by a special tax of $30 per parcel with an annual 1.5% cost of living increase as approved by the voters in June 2005. The current special tax rate is $34.82 per parcel. Services had previously been provided through Fire Station #45. However, this fire station will be closing due to lack of funding and future services will be provided by the nearest available fire station. Data for 2012 is not available as there was a change in interpretation of reporting standards which returned in 2013. Additional information on the District can be accessed via the link below."
There was nothing official until now.