This unbelievably challenging trail is not recommended for anyone. But if you must, have a good map and a lot of stamina -- it's only 1.7 miles, but it's steep; 1900 feet. Think climbing a particularly brutal set of stairs for two miles.
If that hasn't scared you away, here's how you do it. From the Scatter Creek trailhead/campground at the end of the North Fork Tieton River Road, fill out your Goat Rocks wilderness permit, and set off. Immediately cross a bridge over Scatter Creek, and walk along flat, wide tread before coming to a fork in the trail in less than 0.1 miles. Take the right one—the left leads to the defunct Tieton Meadows trail, which used to access Bear Creek Mountain across the river.
The North Fork Tieton Trail is relatively straightforward. Hike along through quiet forest, interrupted occasionally by the babbling of several streams whose sources are high above you. If you have any extra room, fill your bottles -- you'll want as much water as you can carry. After a mile of moderate climbing, arrive at a well-signed junction.
To your right, the Hidden Springs trail is (signed Trail 1117) is very faintly visible. If you can see where it starts, head up it. Though initially hard to see, the trail fades in and out of definition; in some places it's easy to follow, in others, you have to look pretty hard to find it. When in doubt, look for it heading uphill -- there are only a few places where it traverses at all.
There are at least three false summits in store for you. The first is a green, marshy area where a stream trickles underground. Shortly afterwards, a rockier, more desert-like atmosphere awaits, and a small saddle makes you think you might be there. Not so.
The final challenge is just below the saddle before the Hidden Springs basin. The trail narrows to a tiny gully, and though the views are the best you've had all hike, you have to keep your eyes down as you make your way uphill. Don't lose your footing here, it's a long way down.
Scramble up and over to an overlook and get your fill of photos before staggering into the Hidden Lakes camp basin. From here, you're only 0.3 miles away from the PCT and many other more scenic, knee-friendly destinations.