7 Mile Boulders

69 boulder problems · Valley-floor alluvium · 10,347 ft

Help locate these routes: survey the wall

What's here

VB to V13, mostly around V2.

1 VB
1 V0
7 V1
10 V2
8 V3
10 V4
9 V5
7 V6
5 V7
3 V8
1 V9
4 V10
1 V11
1 V12
1 V13

Counted from the 69 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 66 Crag only 3

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 Hidden Slab, Trailside Problem (2 climbs, about 60 seconds on Main Warm-Ups) would place up to 11 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

Valley-floor alluvium. Quaternary, younger than 126,000 years.

Mostly poorly sorted coarse sand and pebbly to bouldery cobble gravel in stream channels, flood plains, and low terraces in mountain valleys. Flood-plain and terrace deposits of Holocene age are commonly about 1.3 m or less above present streams (Madole, 1996). Unit locally includes a minor amount of young stream-terrace alluvium (Qg1), colluvium (Qc) and other mass-movement deposits, fan deposits (Qf), and glacial deposits (Qtp and Qti) along valley margins and organic-rich sediments in bogs, marshes, and meadows. Locally may include minor lake sediments. Top of unit probably consists mostly of poorly sorted sand and gravel in nonglaciated valleys. Unit is commonly less than 5 m above the Fraser River and tributary streams near Fraser and Tabernash, Colo., and commonly less than 5 m above present streams elsewhere within map area. Low-lying deposits are prone to periodic flooding. Estimated thickness 5–10 m

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: Valley-floor alluvium. Geology data: Macrostrat (CC BY 4.0), serving USGS and Colorado Geological Survey maps.

On the map since 1903

The USGS has mapped this ground since 1903. 29 historical sheets cover this crag's map point; the oldest is below.

Thumbnail of the 1903 USGS sheet covering 7 Mile Boulders — **USGS 1:62500-scale Quadrangle for Georgetown, CO 1903** · U.S. Geological Survey · 1903 · 1:62,500 sheet
USGS Historical Topographic Map Collection · Public domain · the record · placed by its coordinates

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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, 1903 to 1983: USGS topoView.

From the archives

Photographs of this area held by the Library of Congress, oldest first. Every one carries the Library's own "no known restrictions on publication"; anything else is left out.

Georgetown & vicinity · Chamberlain, W. G. (William Gunnison) · 1878 · stereograph
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive

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