Use the directions on the main page to get to the trailhead.
From the lower 2WD trailhead (8300 ft), hike uphill on a 4WD road for two miles until reaching the upper trailhead (9900 ft). Once at the upper trailhead there will be a small circle drive with a small parking area. The wilderness area begins at this point.
From the upper 4WD trailhead, hike south on a well-maintained trail through a conifer forest. The trail and ascent will be gradual and very pleasant. After two miles from the 4WD trailhead, the saddle between East Spanish Peak and West Spanish Peak will be reached (10,200 ft). Good camping areas are available at the saddle. Once at the saddle, a wooden post will greet you. This post used to have a sign which said, "Las Animas Co", but now the sign is apparently gone. However, the post is still there and it means that you are now in Las Animas County, Colorado. (Thanks to Arctic Blonde for the the updated route info in August 2007) If you find yourself hiking downhill in a southerly direction, you've gone too far and missed the wooden post.
Anyway, immediately after the wooden post, there is a trail intersection. Go left (east) at the intersection and hike along the flat saddle for about a half mile. Great camping can be found all along this section. From the wooden post, the trail is not maintained and is basically a climber's trail. The trail is faint at times but cairns are there to guide the way. After a half mile or so on the flat saddle, the trail descends slightly into a drainage, then begins a relentless 800 ft climb in 1/4 mile up the north side of the west ridge. This climb eventually attains the west ridge and you will be rewarded with great views of the north and south of the ridge once on top. Follow the west ridge to treeline at 11,600 ft where the trees end abruptly and the talus begins.
UPDATE 8-16-12: After getting to the saddle, the directions are fine except that there are two trails to the ridge. One goes straight up and it relentless, as claimed. A few hundre feet to the right (south), however, there is a well marked path with switchbacks that is much easier. This is the one you should take if you want to have an easier time attaining the ridge. Also, be aware that when you drive to the lower trailhead you pass a "dead end" sign which you should ignore. When you see the sign for the Wahatoya trail pull over to the right, don't make a right, unless you want to go up the jeep trail. (Thanks to Stanjl50)
The talus on the summit ridge is fairly stable. It starts a bit loose, but quickly becomes enjoyable climbing. The first pitch is steep and culminates onto the final summit ridge. Once on the final summit ridge, meander across blocky terrain as you approach the last steep section. At times, hands may be needed for balance; otherwise, it's a hoot. The final summit grunt is the last slap by the mountain as you head for the ending cairn. Enjoy views of the Crestones, Blanca group, and the rest of the Sangres. Descend your route.
Round trip is 11 miles with 4300 ft elevation gain from the lower (2WD) trailhead.
Day hike gear including good rainwear. Water is available at two places prior to reaching the saddle.