Skip to the lesson
Bryce Canyon ConservancyOffline field notes / 01
Saved reading edition03 October 2026 · v1.0.1Reading + interaction included

The changing rock

A hoodoo is a moment.

Follow a rock wall as spaces open, connections disappear, and columns stand apart.

Look for the spaces as well as the stone. This four-frame sequence helps you recognize forms in the landscape. It is a teaching illustration, not the measured history of one hoodoo.

A broad plateau edge with fractures reaching down through rock layersOriginal BCC teaching illustration reused from the geology field notes; not to scale or a measured reconstruction.

01 / Fractures

Start at an exposed edge.

Cracks give water a way into rock. Freezing water can widen fractures; slightly acidic water can dissolve carbonate minerals.

Two thin rock walls stand between channels where material has been removedOriginal BCC teaching illustration reused from the geology field notes; not to scale or a measured reconstruction.

02 / Fins

The edge becomes divided.

As material is removed along fractures, narrow walls remain. Rock layers respond unevenly to weathering and erosion.

A hole in a narrow wall makes a window, with rock still bridging the openingOriginal BCC teaching illustration reused from the geology field notes; not to scale or a measured reconstruction.

03 / Windows

An opening lets the sky through.

A window may develop in a wall. Rock still connects the two sides above the opening.

Separate irregular columns remain after the connecting wall is lostOriginal BCC teaching illustration reused from the geology field notes; not to scale or a measured reconstruction.

04 / Columns

A column remains, for a time.

When a connecting span is lost, separate columns can remain. Their shapes continue to change.

All four views are original BCC illustrations reused from the geology field note. Not to scale, not a ground scan, and not a stability forecast. Read from established public viewpoints; this lesson supplies no route or current access information.

Complete reading edition. All stages and answer notes are visible.

Two processes, working together

Weathering breaks rock down where it sits. Erosion moves the loosened material away. They help explain the forms above, but a drawing cannot tell you how quickly a particular column will change.

Try an observation

Choose a drawing above. Name one visible feature without explaining it: an opening, a narrow neck, or a projecting ledge. Then write a separate question about how it formed.

Try it yourself

Look first. Explain second.

Which sentence records a visible feature without claiming its cause or future?

Read the choices and explanations in the answer notes below.

Choose an answer when interaction is available.

Answer notes · also included in print
  1. A wider ledge sits above a narrower section.
    Yes. This records a shape you can point to. The cause of that shape is a separate question.
  2. Ice alone carved this exact column.
    That proposes a cause. A shape alone does not identify every process that produced it.
  3. This column will fall next winter.
    That is a prediction. These illustrations contain no evidence for a failure date.

Sources travel with the story.

The lesson, diagrams and answer notes are inside this file. Links marked Online need a connection. Linked pages are not included and can change after this edition was saved.

HoodoosOnline

https://www.nps.gov/brca/learn/nature/hoodoos.htm

National Park Service · Bryce Canyon · Updated 2021-09-04 · Checked 2026-10-02

Deposition, uplift, weathering, erosion, ice wedging and the walls–windows–hoodoos teaching sequence.

Facts paraphrased through existing BCC educational text. No NPS photograph, illustration, logo or page reproduction included. A general process explanation, not a clock or a stability assessment for an individual formation.

Geodiversity Atlas: Bryce Canyon National ParkOnline

https://www.nps.gov/articles/nps-geodiversity-atlas-bryce-canyon-national-park.htm

National Park Service · Geologic Resources Division · Updated 2024-06-17 · Checked 2026-10-02

Claron Formation, Paunsaugunt Plateau setting, fractures and differential erosion.

Source facts and an explicit outbound link. No agency media copied. A regional introduction, not identification of rock units from color alone.

Artwork, rights & this edition

Fractures — Original BCC vector artwork; reused from the copied geology field notes. Copyright retained; no new public license grant.

Fins — Original BCC vector artwork; reused from the copied geology field notes. Copyright retained; no new public license grant.

Windows — Original BCC vector artwork; reused from the copied geology field notes. Copyright retained; no new public license grant.

Columns — Original BCC vector artwork; reused from the copied geology field notes. Copyright retained; no new public license grant.

Typography uses locally installed system fonts. No font files, third-party software, star data or source photographs are included.

Original BCC code and editorial adaptation. Copyright retained by the owner; no new public license grant. No rights claimed in U.S. Government source facts.

Version 1.0.1 · Content edition 2026-10-03. Answers stay only in this open page and reset when reopened. No service worker, tracking or automatic source updates.