Deep Cut Guide

Tonnere Tower

38 routes · granodiorite (Boulder Creek Granodiorite) · 7,023 ft

Take me there Routes ↓ Directions

Help locate these routes: survey the wall

What's here

5.6 to 5.13, mostly around 5.10.

  1. 2 5.6
  2. 5 5.7
  3. 7 5.8
  4. 4 5.9
  5. 15 5.10
  6. 3 5.11
  7. 2 5.13

Counted from the 38 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

Base placed (one source) 1  Position on wall known 37 

The order of the climbs along this wall is known from the open catalogue, so a few surveys go a long way: standing at Up and Left - Lone Unknown Route, Clean Sweep (2 climbs, about 60 seconds on Sport Land) 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.

The guidebook for this area

Boulder Canyon Rock Climbs - Topher Donahue - 4th ed. - 2024 every crag it covers

From the publisherBookshop.org

Bookshop.org links are affiliate links: if you buy through one we earn a commission, at no extra cost to you. Bookshop.org gives its profits to independent bookshops.

The book has the topos, the descriptions and the local knowledge this page can't. Buying it helps support the people who know the crag best.

Rock, from the geologic map

Granitic rocks of 1700-m.y. age group (Boulder Creek Granite, Cross Creek Granite, Denny Creek Granodiorite, Kroenke Granodiorite, Browns Pass Quartz Monzonite, Powderhorn Granite, Pitts Meadow Granodiorite, Bakers Bridge Granite, Tenmile Granite) — granite, minor granodiorite, quartz monzonite. Paleoproterozoic, about 2,500 to 1,600 million years old.

Includes Boulder Creek -M.Y. AGE GROUP (AGE 1650-1730 M.Y.)--Includes Boulder Creek, Cross Creek, Denny Creek, Kroenke, Browns Pass, Powderhorn, Pitts Meadow, Bakers Bridge, and Tenmile Granites, Quartz Monzonites, or Granodiorites; also, unnamed granitic rocks

This is the map unit under this crag's map point, read from the 1:500,000 sheet (Horton and others, 2017, U.S. Geological Survey Data Series 1052). 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 500 m wide on the ground, so the wall itself may be the neighbouring unit. The rock named at the top of this page comes from the public geology of this area; this card is the map's answer. Every crag on this unit: Granitic rocks of 1700-m.y. age group. Geology data: Macrostrat (CC BY 4.0), serving USGS and Colorado Geological Survey maps.

On the map since 1902

The USGS has mapped this ground since 1902. 28 historical sheets cover this crag's map point; the oldest is below.

Thumbnail of the 1902 USGS sheet covering Tonnere Tower
USGS 1:62500-scale Quadrangle for Boulder, CO 1902 · U.S. Geological Survey · 1902 · 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, 1902 to 1984: USGS topoView.

In print since 1877

  • 1877 Geologic Map of Colorado (Hayden), high-resolution scan · F. V. Hayden; scan by the Colorado Geological Survey · 1877

    The whole-state sheet of the 1877 atlas, scanned at full resolution by the state survey and free to download.

    Colorado Geological Survey (publication HM-01-04) · Public domain · read it

  • Geological and geographical atlas of Colorado and portions of adjacent territory · F. V. Hayden, U.S. Geological and Geographical Survey of the Territories · 1877

    The first geology anyone drew of this ground. Hayden's survey mapped the state in the 1870s; these are the sheets, with the rock units coloured as they understood them then.

    Internet Archive (Brigham Young University copy) · Public domain · read it

  • Trail and Timberline, volume 2 (1918) · Colorado Mountain Club · 1918

    The Colorado Mountain Club's own magazine in its sixth year, with the club's outings and ascents as its members wrote them up at the time.

    Internet Archive (Brigham Young University copy) · Public domain · read it

Free to read: public domain or government work. About Boulder as a whole, not this wall. More in the reading room.

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.

Boulder, Colorado
Boulder, Colorado · Detroit Photographic Co. · 1900 · photochrom
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

'Neath majestic granite walls and by the rushing mountain stream, Boulder Canyon, Colo., U.S.A. · 1901 · stereograph
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

Boulder Falls, Boulder Canyon, Colorado · 1903 · postcard
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

Chautauqua Grounds, Boulder, Colorado · 1903 · postcard
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

The perfect tree, Boulder Canon, Colo. · 1906 · stereograph
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

South Boulder Valley, Colorado · 1907 · postcard
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

Birds eye view of Boulder, Co. · Haines Photo Co. (Conneaut, Ohio) · 1908
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Boulder, nestling between mountain and plain, Colorado · 1908 · stereograph
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

Overlooking the little city of Boulder, Colorado · 1908 · stereograph
Library of Congress, Prints & Photographs Division · Public domain · the record · found by place name, not yet checked
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

A peep at Boulder, Colorado · 1909 · stereograph
Library of Congress, Prints & Photographs Division · Public domain · the record · indexed to this place by the archive
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

3 more at the Library of Congress.

Photographs near this crag

Taken within 1.5 km of this crag's map point and published under a licence that lets us show them, from Wikimedia Commons. The coordinates say where the camera was, not what it was pointed at, so some of these will be the creek or the trail rather than the rock.

Tyrolean traverse in Boulder Canyon - 1
Tyrolean traverse in Boulder Canyon - 1 · Andrew Magill · 2011 · 442 m from the crag's map point
Wikimedia Commons · CC BY · the record · placed by its coordinates
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

Water fall CO · Hellokitty6688 · 2022 · 130 m from the crag's map point
Wikimedia Commons · CC BY-SA · the record · placed by its coordinates
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Hidden as soon as you tell us, everywhere it appears, before anyone reviews it.

Routes

Also within 3 km

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.

Pick a photo from your camera roll rather than taking one here: a picture taken inside a browser usually has no location saved in it, and we check that the photo was taken at this crag before publishing it. Photos of guidebook pages and topos are refused — they're the author's work. By sending one you're letting us publish it.

Nobody reviews these before they appear, so anyone can report one and it's hidden straight away — including you, if you change your mind, and including a photographer who finds their own picture here.

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.

Sun today
Wall direction not known yet.
Rain & forecast
0 mm of rain in the last 48 hours.
11-11 55°/39° · 0.0 mm · 12 mph · pm storms 0% 11-12 55°/38° · 0.0 mm · 9 mph · pm storms 0% 11-13 57°/40° · 0.0 mm · 11 mph · pm storms 0%
Open-Meteo, fetched 2026-11-11 18:40 UTC

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

Emergency: call 911. Read out your location: Works without signal. If GPS fails, this crag's approximate map point is 40.00380 N, 105.40580 W (Tonnere Tower). That point can be off by hundreds of metres, so say so.

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.

Nearby, from OpenStreetMap

Mapped parking
86 m away (map)
Campsite
Unnamed, 4,689 m away (map)

Distances are a straight line from this crag's map point, which can itself be hundreds of metres off; a road may be much longer. Mapped by OpenStreetMap contributors (ODbL), so a toilet missing here may simply be unmapped. Parking here is what OSM has drawn nearby, not a guidebook's directions.

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