West Needle Mountain is a lengthy enough day as it is, so we did it as a stand-alone route from a base camp at Crater Lake. Circle around the north end of the lake and pick up the trail through the willows to the small tarn at 11,750 ft., southeast of Crater Lake. From the tarn, head southeast, down the beginning of Watertank Canyon, utilizing some trail for a while. Stay mainly in the middle of the drainage, initially. There are some willows but they are low and easy to deal with. After losing about 400 feet in elevation, the trail fades away and you will come to a place in the drainage where it plunges away steeply. This is probably around 11,400 ft. At the headwall, direct yourself to the right, skirting above the headwall and walking through the forest for a ways. You may pick up a faint trail that will lead you out to an open meadow area with sparse trees. The grass here is tall as you continue downward. Towards the lower end of this meadow, we found a cairn that marked where a trail headed off to the southwest contouring across the open, grassy slope. Hopefully that cairn is still there. This trail is easy to follow once located and leads right to the creek that drains the small, unnamed lake, east of and well below the Twilight Peak summit.
At the creek, (which does not show on the USGS map), wander around through the trees and willows, staying on the west side. This will lead to a split in the drainage. Exit the watercourse and head up a dry, grass & tundra filled gully to the left. Make your way up toward the saddle south of South Twilight, that is easy to identify with a large, pointed gendarme. The climb/hike up to the saddle is across familiar territory now, if you descended off South Twilight Peak this way.
Pause at the saddle to discuss your options for climbing West Needle and to take some photos. Some may want to abandon our suggested route here. One option discussed in some sources leads over to the south end of the saddle between West Needle and an unnamed twelver at 12,932 ft. From here, it is reportedly a 3rd and 4th class scramble to the summit. From our perspective, it appeared steep and questionable. Another option is to head toward the great couloir that divides the northwest face of West Needle, highly visible from this saddle and Twilight Peak.
For that option, descend the couloir in front of you, heading down toward the unnamed lake below the northwest face of West Needle, that sits at the head of Twilight Creek. It was easiest to descend on the left side of the couloir for a while and we utilized that knowledge on our return. At the lake, take a break and empty your boots of pebbles and dirt from the descent. From near the lake, head toward the great couloir, but don't head directly into it yet. Save yourself some grief and utilize some tundra on the left side of the talus cone at the base of the couloir and ascend along the edge of the rocks to the top of the cone where there are some cliffs. Cut along the base of the cliffs at the head of the talus cone and then drop into the main couloir. Follow the great couloir all the way to the summit, a task much easier said than done. While it was fairly steep and always filled with rocks & rubble, the going was never too difficult, so just keep with it and struggle on. We should add that earlier in the season, this couloir would undoubtedly be filled with snow and would make an excellent snow ascent – not too steep or difficult. Ice axe and at least micro-spikes advised. The couloir tops out between two flat summits. We visited both with strong winds and partly cloudy skies. The map shows the south summit as the highest, with an elevation of 13,045 ft., but we found a cairn and summit register on the north. Apparently G&M felt the north summit was higher and gave it an interpolated elevation of 13,062 ft. That elevation has since been used. The register had been in place since 2001 and only about 4 or 5 people a year had signed it. It had taken us a little under 4 hours to arrive here from the Crater Lake campsite.
To return to camp, go back down the same couloir you ascended in. There is unfortunately no scree that you can plunge-step down so you must take it more slowly. Nevertheless, I think we were down in about 45 minutes and then headed back up to the gendarme saddle south of S. Twilight. Going back up the 700 feet was not all that bad. We started back up, not in the couloir but to the right on tundra slopes and followed those slopes for a good distance up before dropping into the couloir. Then we held to the right side where footing seemed best and there was a rock wall to grab for an assist. At the saddle, hike down the tundra and then the rock and pick up the trail you followed in in the morning. Retrace your route back to Crater Lake.
Bonus Points: There is a high-ranked twelver just north of West Needle. UN12,932 ranks as #693 and is a fairly easy, Class 2 ascent from the gendarme saddle by contouring SE from that saddle over to another saddle, then ascending the NW ridge of the peak.
Links to other information, routes & trip reports for this peak that may be helpful.