From the Fourth of July trailhead on the north side of the parking lot, follow the signs for the Arapaho Pass trail
1 to start. The trail starts out with a gentle climb
2. There are plenty of social trails, side trails, and closed-for-rehabilitation previous trails, so stick with the clear and heavily trodden trail when in doubt. The trail climbs about 500 vertical feet in easy class 2 terrain
3 in the first mile. Step carefully over various small streams.
Around 1.1 miles at 10,750 feet you reach the junction of the Diamond Lake trail. Stick with the Arapaho Pass trail
4.
At 1.5 miles, around 11,100 feet, the trail goes almost level for half a mile of beautiful scenery
5. At 2.0 miles and 11,200 feet, you'll reach the ruins of the old Fourth of July pit mine and the juncture of the Arapaho Glacier trail
6, a much smaller trail than the Arapaho Pass trail. Take care to make this right hand turn onto Arapaho Glacier trail.
Within a few feet you'll cross a substantial stream or marshy area
7, pass a large boulder
8 and then continue your ascent
9 10 gradually gaining altitude. You'll pass through 12,000 feet about 3 miles from the trailhead
11. South Arapaho Peak's summit comes into view to the northwest
12 and Old Baldy's summit comes into view to the northeast
13.
To summit Old Baldy to the northeast, you can continue on the Arapaho Glacier trail
14 to the saddle between Old Baldy and South Arapaho Peak and then go east off-trail to Old Baldy's summit, or you can take a more direct line off-trail to Old Baldy's visible summit
15.
As you ascend Old Baldy, you can see the ridge up South Arapaho Peak to the west
16. After achieving the summit of Old Baldy
17, head west to the saddle between Old Baldy and South Arapaho Peak
18.
Ascend between the cairn
19 and the cliffs that drop onto the glacier. Follow the ridge line
20 to the false summit. The terrain becomes more difficult here
21 and to keep it as class 2, you'll have to pick your route carefully. Comfort with a few class 3 moves gives you some more flexibility in route over the rocky scramble.
The true summit becomes visible from the false summit
22. Follow the ridge line to gain the true summit
23 and locate the geo-marker.
The ridge line continues on the route to North Arapaho Peak, but the route becomes Class 3 and Class 4 rock from here.
On the return route, follow the ridge you ascended back to the saddle between South Arapaho Peak and Old Baldy. At the saddle you can rejoin the Arapaho Glacier trail heading southeast (not due east) and follow it back the way you came to the Arapaho Pass trail and finally the trailhead.