The Atlas: measured, derived, and interpreted
The terrain and landmark assets are the existing BCC models. Elevations derive from USGS 3DEP lidar acquired in 2018, with heights in meters referenced to NAVD88. The overview uses USDA NAIP aerial imagery acquired in September 2021. Colors, lighting, and fine surface textures are processed or drawn; they are not fresh observations.
The north-up locator uses the same OpenStreetMap landmark positions as the 30 km terrain. It is a location diagram, not a trail or boundary map. Switching to a landmark changes scale and origin. It does not simulate a continuous measured flight through the intervening terrain.
| Scene | What is represented | Important limit |
|---|---|---|
| Landscape | 30 km square, true vertical scale; finest mesh in the central 4,096 m. | Distant terrain is coarser. Elevation colors are not formation boundaries. |
| Thor’s Hammer | Lidar surfaces, plus a neck outline from an NPS photograph. | Hidden depth and bed resistance are interpreted. Beds have not been sampled. |
| Natural Bridge | Lidar and an opening interpreted from a USGS photograph dated December 17, 2014. | The opening is simplified through the fin. The four formation stages are illustrations, not dated past shapes or a forecast. |
| Queen’s Garden | A 432 m heightfield, OSM trail and lidar ground profile. | A heightfield misses overhangs. The trail may be displaced by several meters. Generated mesh spacing is not survey accuracy. |
For acquisition records, processing, rights, and model measurements, read the existing terrain, Thor’s Hammer, Natural Bridge, and Queen’s Garden methods. Public data and source credit imply no agency endorsement.
Deep Time: an explanatory sequence
The lake, burial, uplift, weathering, and hoodoo drawings are original BCC schematics. They show relationships between processes; they do not reconstruct a specific shoreline, sample local beds, model a fault, or calculate erosion. Patterns and text distinguish materials as well as color. Bed count, thickness, topography, grains, arrows, and perspective are illustrative.
Chapters divide a story, not uniform slices of geological time. Deposition, lithification, deformation, exposure, and erosion can overlap. Playback gives each chapter the same reading time; it does not imply equal geological duration. The final landscape image returns to the acquired terrain dataset.
Why the time labels are qualified
The NPS Hoodoos introduction places the lake and floodplain story around 50 million years ago. That is the orientation marker used here. It is not a precise date for the entire Claron Formation.
Agency summaries differ: the Sunset Point wayside uses 50–60 million years; the park brochure describes a basin between 55 and 40 million years ago; a 2023 UGS regional account describes the Claron as Paleocene–Eocene, about 65–35 million years. These introductory numbers use differing scope and should not be averaged into a new date.
Likewise, the NPS wayside emphasizes tectonic change around 20 million years ago, while its Hoodoos introduction emphasizes later rise to modern elevation. Our uplift chapter follows the order and overlapping processes, without assigning one date or a numeric uplift rate. A professional review should refine the local chronology before any more precise reconstruction.
The regional section
The Bryce–Zion–Grand Canyon picture is schematic: distances, slopes, and bed thicknesses are not to scale, and the colors are not a formation inventory. It follows the broad NPS Grand Staircase account and the Kaibab connection. Missing time, faults, and changing depositional settings prevent treating the parks as one unbroken, uniform stack.
Primary reading
- NPS · Hoodoos (updated September 4, 2021): sediment, uplift, cementation and weathering.
- NPS · Bryce Geodiversity Atlas (June 17, 2024): Claron, joints, differential erosion and geological inventory.
- NPS · Sedimentary rocks: how sediment becomes rock.
- UGS · Utah’s geologic history: regional tectonic and depositional context.
- UGS · Mapping hazards near Bryce (Tyler Knudsen, May 2023): the Claron, drainage contrast, ongoing erosion, and geologic hazards.
- Bowers / USGS · I-2108 (1991): published geological map and report. This Atlas does not display a mapped-geology overlay.
Sources checked October 1, 2026. The USGS I-2108 landing record was accessible; its linked report and plate downloads were unavailable during this refresh. No new claim of map-legend validation is made. The existing Claron field note retains its earlier reading record.
Review still open
No independent geologist review is recorded. Focused review questions are: Does the lake/floodplain treatment represent the relevant Claron environments fairly? Are the age qualifications adequate? Does the uplift sequence avoid implying a single event? Do the sections make the distinction between mapped units and interpreted beds clear?
The models do not establish safe access, rock stability, a landmark’s failure date, land ownership, or a partnership. Use established trails and current park guidance.