BTW, access from the other side (coming in Hampton/Sierra Pacific land from much farther south on Mosquito Lake Rd) is getting attention as a more legitimate access point under the auspice of visiting the DNR Daley Prairie Nature Area Preserve. Its 3-4 times longer but all bike-able.
https://www.dnr.wa.gov/dailey-prairie-natural-area-preserve
https://www.gaiagps.com/map/?loc=12.1/-122.0436/48.7031&pubLink=HvWt3tXDN4hxcctmlr5OsnYq&trackId=52e0a40a-30fe-4eb5-8baa-692cb581c84c