Basin and Range

Origin at a former dam structure. Concrete arch, intact, approximately 220 m span across a dry canyon. Spillway channels are dry and have been for an extended period—sediment accumulation in the stilling basin indicates decades without significant flow. A gravel road descends from the dam crest along the eastern canyon wall. The track crosses the former reservoir bed, now alkaline flat, for approximately 80 km. Surface is hard-packed silt with a salt crust. Bearing capacity is high when dry; when wet, the crust breaks and the substrate becomes impassable. Do not cross after rain. Beyond the dry lake, the terrain rises gently through sparse creosote and juniper. A series of low passes between eroded ranges, none exceeding 1,500 m. Road surface is desert pavement—interlocking cobble, slow but stable.

Surface

40% hard-packed silt, 35% desert pavement, 25% gravel

Max. gradient

8%

Obstacles

2 >300 mm (wash crossings with soft sand)

Canyon country. The route enters a region of deeply eroded sedimentary formations. Sandstone walls rise 200–400 m on either side of the track for extended stretches. The road follows dry wash bottoms where canyon width permits, and climbs to shelf roads along the walls where it does not. The shelf road sections are narrow—single vehicle, no margin on the drop side. Three wash crossings in this segment have soft sand bottoms that require momentum to cross; deflate tires to 150 kPa or lower for traction. A natural arch formation spans the canyon at km 440, approximately 60 m above the road. The arch is sandstone, intact, not load-bearing for the route. Beyond km 480, the canyons widen and the terrain opens to mesa tops.

Surface

15% degraded asphalt, 40% rock/gravel, 45% sand

Max. gradient

16%

Obstacles

5 >300 mm / 2 >500 mm (shelf road erosion, boulder fall)

Mesa and volcanic terrain. The route ascends to a high plateau at approximately 1,800 m. Surface is basalt rubble in the western portion—sharp, angular, reduce speed to limit tire damage. Tire pressure should be adjusted upward to 220 kPa or above on basalt surfaces to reduce sidewall exposure. The plateau is flat and open; navigation is straightforward. At km 640, the remains of a former settlement are visible from the road: concrete foundations, a grid pattern of roads partially visible beneath grass and rabbitbrush, no standing structures. Beyond km 700, the terrain transitions to a broad basin between two volcanic remnants. Cinder cone visible at km 730, approximately 200 m in height, recent enough to retain its form. The track skirts the base of the cone on its northern side.

Surface

20% basalt rubble, 30% gravel, 30% soil, 20% degraded asphalt

Max. gradient

12%

Obstacles

4 >300 mm / 2 >500 mm (basalt ledges, wash erosion)

High plateau, open terrain. The route crosses a broad, gently undulating plateau between 1,600 and 2,000 m. Vegetation is sparse sage and bunch grass. Road surface is gravel over compacted soil, in better condition than preceding segments—the track here follows a former two-lane road that remains largely intact. At approximately km 890, a cluster of structures is visible on an elevated terrace to the south of the route: steel frame, rammed-earth walls, extensive photovoltaic skin covering the south-facing surfaces. The structures are clearly operational—reflective surfaces are clean, no vegetation encroachment on the array, access road from the main track shows regular vehicle use (tire impressions, compressed surface). Three buildings of varying size, the largest approximately 30 m in its longest dimension. Function not determinable from the road. The route continues east past without approach.

Surface

35% degraded asphalt, 40% gravel, 25% soil

Max. gradient

6%

Obstacles

1 >300 mm (road washout at drainage crossing)

Descent from the plateau into a series of north-south trending valleys. The terrain becomes more rugged as the route approaches the higher ranges to the east. Three significant passes in this segment, elevations 2,100 m, 2,200 m, and 2,340 m. The highest pass at km 1,180 has sustained gradient of 18% on the eastern ascent—loose gravel surface, low-range gearing required. A canyon ford at km 1,120 is the deepest on the route: 450 mm at seasonal median, +200 mm in spring when upstream snowmelt increases flow. The ford bottom is cobble over bedrock; traction is adequate. Between km 1,140 and km 1,160, instrument anomalies are consistent and reproducible. Compass deviation exceeds 15° without apparent external source. Onboard navigation systems provide erratic position data. The source of the interference is not identifiable from the terrain—no visible infrastructure, no geological explanation consistent with the observed effect. Stellar or landmark navigation required. Visible reference points: a distinctive rock spire at bearing 042° from km 1,140, the pass summit at bearing 078°.

Surface

15% degraded asphalt, 55% gravel/rock, 30% soil

Max. gradient

18%

Max. ford

450 mm (+200 mm spring)

Obstacles

5 >300 mm / 3 >500 mm

Eastern approach to the continental divide. The terrain rises steadily through piñon-juniper woodland into mixed conifer. Road condition improves with elevation—the former road surface is better preserved in the cooler, drier climate above 2,000 m. A long valley at km 1,400 provides a corridor between two high ridges; the track follows a seasonal stream bed for approximately 30 km. In spring, the stream is active and the track is partially submerged—ford depth up to 300 mm, mud substrate, differential lock recommended. In summer and autumn the stream bed is dry and the gravel surface is firm. The final approach to the terminus is a gradual descent through aspen and spruce. The terminus is a maintained compound at the base of the divide: three structures of varying size, the largest with a metal roof and solar array, a cleared vehicle staging area, and tire tracks indicating recent and regular use. This compound is also the origin of the Divide Transit route.

Surface

25% degraded asphalt, 50% gravel, 25% soil

Max. gradient

10%

Obstacles

1 >300 mm (seasonal stream bed crossing)