From the summer trailhead, cross the bridge that spans the stream in Stevens Gulch and follow the well-defined Grays trail up the hill into Stevens Gulch.
1 is the view of Grays from near 11,700'. Continue on the Grays trail for nearly 1.5 miles until you are near the trail sign near 12,100'. Just before the sign, locate a small road that leaves the left side of the Grays trail -
2. Follow the small road down a bit and then south towards the center of the basin.
3 is another close-up view of Lost Rat. After heading south for a bit, continue on the road as you approach the southwest end of the basin -
4. Stay on or near the road as it climbs onto the talus below Lost Rat -
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6. Hike over to the base of the couloir -
7. Crampons, axe, helmet, and avalanche gear are recommended.
Start climbing. Above 12,800', the terrain steepens as you approach the confines of the couloir -
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10. Above 13,100', reach a fork in the couloir -
11. Stay left and continue up the main couloir. The next 300 feet is straightforward and the slope angle reaches 45 degrees -
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14. Near 13,500', the couloir turns slightly left as you pass through the narrowest section -
15. Climb the last 100 feet to reach the top of Lost Rat -
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17. Turn right (west) to see the remaining 700 feet up Grays' east ridge -
18. Follow the ridge to the summit -
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