drekin: Based on the lack of snow on the Main Trail, the MR should be mostly clear, too. I wouldn't take the crampons or the ice axe. The final 400 should be clear enough to avoid what ice there is.
On your last question: No, it is not well marked! It is a "route" and NOT a trail. The Inyo N.F. website is extremely misleading. I've tried to get them to change it, but there is some bureaucratic reason for what they have. Here's the description from this link:
Quote:
The North Fork Lone Pine Creek Trail is in the John Muir Wilderness. The trail is steep, rugged and difficult to follow. It provides access to Mt. Whitney's Mountaineers Route, East Face and East Buttress, as well as to Mt. Russell's Fish Hook Arête and East Ridge. The trail ends at Iceberg Lake, at an elevation of about 12,600 feet.
Let me repeat: There IS NO TRAIL. There are a few places where you will find a well-beaten use-trail, but for lots of it, if you do not understand where you are going, you will just be lost. If you start in the dark you are fine up to the North Fork L.P. creek. Then there is a path to follow another 15 minutes. Then paths split. Both splits come come together at the base of the Ebersbacher Ledges. A first-timer should NOT attempt the Ledges in the dark.
