Naches Trail passes over Naches Pass. Open Seasonally July 15th through November 15th. The trail is very busy the first and last weekends it is open each year.
The trail includes 3 sections, the westside's Lower Naches being the most difficult, there's the pass section which includes the cabin at Government Meadows, and then the East Side which takes the trail down to the FS1913 and FS 70. The Naches trail crosses over FS70 multiple times.
You'll need to go with someone who's been there to find the actual start of Lower Naches. Its found on one of FS70s many lefthand spurs. Also located here: 47° 6'15.20"N 121°27'53.25"W Lower is significantly more challenging than the rest of the trail, especially when wet. 33s and a locker or lots of skinny pedal will be needed. I've seen dual sports on this trail frequently so it is possible for advanced riders.