Mountain Air Ranch Boulders
6 boulder problems · Biotite gneiss · 7,160 ft
What's here
VB to V3, with no single grade dominating.
Counted from the 6 climbs here that carry a grade. Shown only where there are at least 5 of them — below that the shape is noise.
How well located
Position on wall known 6
No route here has its own point yet. The map pin is the crag. At the wall? Survey it: 30 seconds per route.
The order of the climbs along this wall is known from the open catalogue, so a few surveys go a long way: standing at Native Ladder, Slab Line (2 climbs, about 60 seconds) would place up to 4 more climbs between them. Survey the wall →
“Up to” because the estimate between two surveyed routes is only used when they turn out to be close enough together on the ground.
Rock, from the geologic map
Biotite gneiss. Paleoproterozoic, about 2,500 to 1,600 million years old.
Gray, medium-grained, equigranular, well-foliated gneiss typically containing approximately 25–50 percent quartz, 20–30 percent plagioclase (approximately An30), 0–30 percent microcline, 10–15 percent biotite, 0–15 percent muscovite, 0–10 percent sillimanite, 0–5 percent hornblende, 1–2 percent opaque minerals, and a trace zircon. Most outcrops contain 5–20 percent granitic layers (leucosomes). Sillimanite, where abundant, occurs in fibrous, elongate, light-colored aggregates or clots as wide as about 1 cm. Migmatitic biotite gneiss in Clear Creek gave preliminary U-Pb zircon date on nonmelt phase of 1,773±18 Ma; near Pine, just south of map area, similar rock gave U-Pb zircon date of 1,780±9 Ma (W.R. Premo, unpub. data, 2005)
This is the map unit under this crag's map point, read from the 1:100,000 sheet (Kellogg and others, 2008, USGS Geologic Investigations Series 3000). The point can be a few hundred metres from the rock, a cliff often stands on the line between two units, and at that scale a line on the map is about 100 m wide on the ground, so the wall itself may be the neighbouring unit. Every crag on this unit: Biotite gneiss. Geology data: Macrostrat (CC BY 4.0), serving USGS and Colorado Geological Survey maps.
On the map since 1899
The USGS has mapped this ground since 1899. 23 historical sheets cover this crag's map point; the oldest is below.
USGS Historical Topographic Map Collection · Public domain · the record · placed by its coordinates
Report this item
Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.
Public domain, U.S. Geological Survey. The sheet shows the ground as the survey found it then, which is why a trail or road you know may be missing. Every sheet over this point, 1899 to 1983: USGS topoView.
Routes
Also within 3 km
- Deer Creek Crag2,477 m · 6 routes and 6 boulder problems · 6,416 ft · Deer Creek Crag
- Deer Creek Canyon Cave2,567 m · 1 boulder problem · 6,412 ft · Deer Creek Canyon Cave
- Birds and the Bees2,746 m · 9 routes · 6,639 ft · Birds and the Bees
- The Urban Alpine Crag2,866 m · 6 routes · 6,342 ft · Urban Alpine Crag, The
Straight line between the two crags' map points, each of which can be some way from its rock. For when this wall is full, or the sun has found it.
Photos from climbers
No photos here yet. If you're at the crag, yours would be the first.
Taken at the crag by climbers and published as they sent them. Each one's own location had to be within 0.5 km of this crag before we accepted it. See something that shouldn't be here? Use Report this photo under it and it's hidden at once. Anything else, write to us.
Conditions reported
Nothing reported recently.
Report what you see
Reports are dated and fade on their own: wet rock after 3 days, a bad bolt after a year. No names, no text.
Access & safety
We don't know who manages this ground: PAD-US doesn't map this point as protected land, which most often means it is private. Find out whose it is before you go.
Nobody has yet read the land manager's own rules for this crag and written them down here, so treat the above as where you are, not as what you may do.
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