There are three main routes used to reach Ah-Shi-Sle-Pah WSA. One is from NM 371
in the west - along county road 7650 for 7.7 miles, south on 7870 for 9.5 miles then northeast on 57 for 2.8 miles. The BLM trailhead used to be at the end of an unsignposted half mile track that forks off northwards, the junction being a short distance west of a lone house to the south, but the track has recently been closed to vehicles, which now have to be left along road 57. Like many of the dirt roads in this area, these three routes are used by trucks from the nearby oil fields so are kept in a good state of repair. The other two approaches are from the east, both starting from US 550
; most direct is via road 57, which forks off the highway at Blanco Trading Post
and reaches the trailhead track 18.3 miles later, after quite a few junctions (all clearly signposted with the road number). The first few miles used to be paved but now the surface is heavily eroded and quite bumpy - driving is easier on the hard-pressed dirt after this, though the road seems rather less used by oil trucks and more by the Navajo, so is not quite as good as others around. The third route is 451/7800 from Nageezi
- fully paved for a few miles but wide and well used for all the 12 miles to the junction with road 57, 3 miles from the trailhead.
The half mile approach track, now for foot traffic only, climbs to the top of a low, bushy ridge then descends the far side to a fence marking the boundary of the WSA. Ahead, the land slopes down quite abruptly by 80 feet and soon becomes completely unvegetated, consisting mostly of multicolored clayish mounds with hoodoos in scattered locations west and northeast. Beyond these formations lies a wide, flat mud plain either side of Ah-Shi-Sle-Pah Wash, bordered one mile away by a similar strip of badlands on the north side. There is a more extensive area of black and yellowish mounds to the northeast, split by many deep, labyrinthyne gullies largely without any eroded rock formations; the best section stretches from the lower edge of these badlands, a short distance east of the trailhead, for about 1.5 miles westwards (see topo map
). Most hoodoos hereabouts consist of reddish sandstone caprocks over white/grey mudstone pillars, but more colorful yellow-orange columns are found towards the west, as are the largest pieces of petrified wood.
One way to explore the area is to walk northeast through the hoodoos around the edge of the branched ravines, then turn west along the flat land at the side of the valley, walking south towards anything that looks interesting, and returning higher up, across the yellowish badlands lining the plateau rim. The eastwards hike passes three tributary ravines, all containing red/white hoodoos and scattered petrified logs, beneath grey-black badlands. After the third and largest of the ravines, the undulating mounds become more extensive, projecting northwards a way, and also more colorful, with patches of orange and yellow in the badlands, and orange bands in some of the hoodoos. Petrified wood is more plentiful, including large trunk sections on the valley floor and logs along the edge of the badlands - here are found some of the upright stumps. Often an intact piece of the wood is surrounded by a small hill of tiny fragments, resulting from disintegration of a much larger part of the tree.
The next tributary ravine appears just beyond a prominent, detached black-topped mound, as the band of eroded formations starts to narrow. The wash draining this area runs over beds of pure black coal and contains oil seeps, producing enough fluid for a shallow oil stream to flow a short distance. The west side of the ravine is bordered by some reddish mounds, marking the approximate end of the hoodoo belt. Walking back along the top of the badlands reveals smaller but still interesting groups of hoodoos and some nice undulating sandstone containing bands of yellow and orange. One characteristic feature of this area is the yellow-black hills just above the hoodoos, made of soft mudstone and split by many narrow ravines. The ground is so soft that rainwater forms vertical sinkholes in the hills and short caves in the ravines, where the flow channel disappears below ground for a while, under piles of mud, making the drainages difficult to walk along. Also, because the hillsides are steep, the surface loose, and sinkholes many feet deep may be covered by a thin roof layer, care is needed if traversing this area. Hiking is more straightforward higher up along the edge of the plateau, which is grassy and sandy.