OverviewThis is a 2nd class route with some moderate brush. The brushier sections are mainly small pine trees and huckleberries. The upper west ridge section is scenic, and overall, this is a straightforward route, albeit a bit long. Expect to encounter a permanent snow field near the summit. This route is similar to what Smoot describes in "Climbing Washington's Mountains." He rates the difficulty as class 2-3. There is no 3rd class climbing required on the route described here. Smoot describes three finishes to his route: straight up the West Ridge,and two easier variations to the south. This route moves to the north side of the ridge to avoid the 3rd class climbing.
In "75 Scrambles in Washington," Goldman describes the ridge from Persis to Index as the primary route. She also describes the logging road approach detailed here, but instead of making the 4700' traverse, that route attains the ridge and follows it, meaning it must drop down and go over the 4900' saddle (WP 011).
My detailed route description refers to way points on the attached topo map, e.g. "WP 014" is the summit way point.
Getting ThereFrom Hwy 2 Sultan P&R:
Drive 11 miles east on Hwy 2 to the junction with FS Road 62 (WP 001). Turn right (south) on FS 62 and drive about 7 miles to the gate/TH (WP 003, 1640').
Mountain Bike: The one way bike mileage is about 6.6 mi, starting at the gate. Follow FS 62 south 1.9 mi to a tee junction with FS 6240 (WP 004, 1425'). Go left (east) for 3.7 mi on FS 6240. Immediately there is a small hill that most people will walk. Proceed east on bikes to WP 006, 2000'. This marks the start of the Index ascent. Walk (or ride) one mi and park the bikes at WP 007, 2570'.
Road walk: Continue on the road for another 2 miles to WP 009, 3960-80'. Look for an easy way to get from the road into the forest. Be careful on the return because there are some cliffy spots.
Scramble: The scramble portion is about 1.5 mi. Slightly before the high point in road at 3960-80', start an ascent in a northeasterly direction bearing 30 degrees through moderate brush (mainly small pine trees and huckleberries) toward WP 010, a clearing with some rocks below a rock wall at 4540'. Climb steeply to the right of the rock wall until about 4725-4750', and then do an almost level traverse, passing by some small tarns on a 4700' grassy bench.
Continue on into the basin below the Pt 5212' – Index saddle, and then climb to the saddle (WP 011, 4900').
From the saddle, follow the ridge crest up through trees, breaking out of the trees onto the ridge's north side on the way to WP 012, 5460'.
Traverse across a steep snow field (may need crampons), and then head up through 2nd class rock to WP 013, 5670'. Walk to the summit, WP 014.
Maps: USGS Index & Gold Bar, Green Trails Index & Mount Si
My topo map and way points use WGS 84 (NAD 83), not NAD 27.
Water: The only source of water is a stream about 0.5 miles after parking the bikes and the small tarns on the 4700' bench. There is also a permanent snow field near WP 012.
Trip statistics: 10 mi to summit, 4670'gain (330' return), 12 hrs car-to-car on 8/18/2007. That's about 20 miles RT, 5000' total gain.
1:30 bike ride/push WP 003 to WP 007
1:30 road walk WP 007 to WP 009
0:45 scramble from WP 009 to WP 010 (brushiest section)
2:45 scramble from WP 010 to summit
total 6:30 cars to summit
0:30 on summit
2:00 summit to WP 010
0:30 WP 010 to WP 009
2:30 WP 009 to WP 003
total 5:00 summit to cars