From the Matterhorn Creek Trailhead, head north into the Matterhorn Creek valley on the obvious trail. At 11,200 feet, a fork in the trail will give you the option of continuing straight or taking a large switchback to the right (east). There may be an uninformative sign here as well. Take the right switchback instead of going straight. The right switchback will soon turn back left (north) and you will proceed up the Matterhorn Creek valley.
Continue heading north up the Matterhorn Creek valley until you reach 11,960 feet. Here will be a signed fork in the trail. Go left toward Wetterhorn Peak. The trail will lead you through a boulderfield where the trail may slightly disappear for small sections. However, cairns will show you the way.
Continue all of the way to the 13,060 foot ridge southeast of Wetterhorn Peak. Follow periodic cairns up the class 2 ridge. You will start on the left (west) side of the ridge, but will end up on the right (east) side of the ridge at some point, eventually reaching the "Ship's Prow", a 30 foot tall prow of rock that rises above a relatively flat area on the ridge below Wetterhorn's summit. Follow the cairns that take you back to the west side of the ridge from here. Once back on the west side of the ridge, you will immediately encounter the final class 3 pitch that leads to the summit of Wetterhorn Peak. Carefully ascend the class 3 wall which takes you directly to Wetterhorn's summit.
Descend Wetterhorn Peak the same way that you ascended. Once back in the boulderfield at an elevation of 12,560 feet, head east across the boulders to the base of the grassy south slope of Wettterhorn Peak. Walk up the grassy slopes to the summit of Matterhorn Peak, navigating through some class 3 terrain near the summit.
Descend Matterhorn Peak's southeast slopes to the trail that leads from Uncompahgre Peak back to Matterhorn Creek Trailhead. Take that trail back to the Matterhorn Creek Trailhead.