The S. Cle Elum Ridge fire road closures have been lifted. They were lifted a week or so ago per the cle elum rangers station phone message.
If you are talking about the private timber land off road 4510 (Plum Creek Timber) you will not be able to access the area via the logging road with any motorized vehicles behind the gate. If you stick to the dirt bike trails they are open to two wheel vehicles only. Pick up a ORV map from the cle elum rangers station and it will show you where you can and cannot go.
I see dirt bikers riding the logging roads back there all the time but if you get caught you will get a large ticket. I confirmed this with WDFW officer and Kittitas County Sheriff last week. Not to mention getting a mouthful from the hunters that spent all morning hiking in.
Probably not what you wanted to hear. Sorry