---
title: "Glacial Lake Prince George: why the city sits in a bowl"
description: "How ice sheets, a vanished glacial lake and two rivers carved the Prince George bowl, its silt cutbanks and the benches the city is built on."
url: https://princegeorgepulse.ca/explore/glacial-lake-prince-george/
markdown: https://princegeorgepulse.ca/explore/glacial-lake-prince-george.md
site: PG Pulse (https://princegeorgepulse.ca), The pulse of Prince George, British Columbia
generated: 2026-10-16T15:54:56.417Z
---

# Glacial Lake Prince George: why the city sits in a bowl

How ice sheets, a vanished glacial lake and two rivers carved the Prince George bowl, its silt cutbanks and the benches the city is built on.

Updated September 30, 2026

![Tall pale silt cliffs, the Nechako cutbanks, rising above the Nechako River in Prince George](https://princegeorgepulse-media.s3.ca-central-1.amazonaws.com/prince-george/guides/tall-pale-silt-cliffs-nechako-cutbanks-rising-above-81824c-1280.webp)

Photo: RadRafe, public domain via Wikimedia Commons

## At a glance

- The ‘bowl’ is a broad valley carved into the Nechako Plateau where the Fraser and Nechako valleys merge.
- About 25,000 years ago an ice sheet roughly 2 km thick covered the Prince George area.
- As the ice melted, meltwater dumped thick sand and gravel, and a temporary lake, Glacial Lake Prince George, flooded the region.
- The rivers then cut down through those deposits, exposing the famous cutbanks and leaving flat ‘benches’ at several levels.
- The same buried gravels hold the aquifer that supplies the city’s drinking water.

Drive into Prince George from almost any direction and you drop off a forested plateau into a wide, flat valley. Locals call it **the bowl**. Along the rivers, pale cliffs called **the cutbanks** rise straight out of the water. Both are leftovers of the last ice age and of a lake that vanished thousands of years ago.

This guide explains the landscape in plain language, drawing mostly on a Geological Survey of Canada geotour of the city. For a shorter read, try our explainer [Why Prince George sits in a bowl](https://princegeorgepulse.ca/articles/why-prince-george-sits-in-a-bowl/).

## The setting: a plateau split by two rivers

Prince George sits on the **Nechako Plateau**, the northern part of British Columbia’s **Interior Plateau**. It is a gently rolling upland built on ancient volcanic rock, later smoothed by lava flows and scoured by ice. Two big rivers have cut valleys into it: the **Fraser**, arriving from the Rocky Mountain Trench to the east, and the **Nechako**, flowing in from the west. Where they meet, the valleys merge into the bowl.

The bedrock is mostly hidden. Along Foothills Boulevard at the base of Cranbrook Hill, you can see greenish volcanic rock about 200 million years old. At the Forests for the World parking lot, granite pokes through. Nearly everywhere else, the rock is buried under thick ice-age deposits.

## Step by step: how the bowl formed

### 1. The ice arrives

Continental ice sheets came and went over the past two million years. At the peak of the last glaciation, about **25,000 years ago**, ice roughly **two kilometres thick** sat over Prince George. It deepened valleys and left a carpet of mixed stones, sand and clay called **till**.

### 2. The big melt

Around **12,000 years ago**, the ice began to break up. Torrents of meltwater carried huge loads of sand and gravel off the bare, unvegetated land and dumped them in the valleys of the proto-Fraser and Nechako. In places these deposits are tens of metres thick. They make up most of the height of today’s cutbanks.

### 3. Plugged: Glacial Lake Prince George

As the ice sheet decayed, lobes of ice could still block drainage routes. With the valleys dammed, meltwater backed up into a large temporary lake that flooded the Prince George and Vanderhoof lowlands. Geologists call it **Glacial Lake Prince George**. Related glacial lakes in central BC, such as glacial Lake Fraser, are described in the scientific literature, and their exact extents and timing are still being refined.

Lakes are quiet places. Fine sand, silt and clay settled slowly to the lake floor, forming layered **glaciolacustrine** sediments (glacio for ice, lacustrine for lake). Around Prince George, that lake-floor layer is a light tan band a few metres thick, visible at the top of the bluffs just below the forest.

### 4. The lake drains and the rivers cut down

Once the ice dams failed, the lake drained and the modern Fraser River was born, flowing south to the Pacific. The Fraser and Nechako began slicing down through the soft ice-age fill. Where they meet, both rivers swung back and forth across their floodplains, eroding a broad hollow. That hollow is the bowl.

### 5. A staircase of benches

Rivers do not cut down in one go. Each time the Nechako and Fraser paused and then cut deeper, they left their old floodplain stranded above the new one. The result is a **staircase of flat terraces, or benches**, at different heights:

- **Connaught Hill**, the flat-topped hill beside downtown, is a remnant of old lake floor and underlying gravels.
- The **Nechako Bench** and **Edgewood Terrace** neighbourhoods along North Nechako Road sit on former river plains.
- The **Otway** Nordic ski area lies on a gravel bench above the Nechako.
- The low floodplain at **Cottonwood Island Park** is the newest step, still flooded by the river from time to time.

Above it all, **Cranbrook Hill** to the west and the plateau surfaces around the airport and the Hart are the original upland the rivers cut into. UNBC’s campus sits on that western rim.

## The cutbanks up close

The most dramatic exposures are the **Nechako cutbanks** on the north side of the river across from downtown, and the bluffs across the Fraser from Lheidli T’enneh Memorial Park. From the park’s riverside path you can read the story from top to bottom:

1. **Forest floor**, a very flat surface: the old bed of the glacial lake.
2. **A pale band of fine sand and silt**, roughly 2 to 3 metres thick: sediment that settled on the lake floor.
3. **Thick layers of gravel and sand**: meltwater deposits laid down before the lake formed.
4. **The river**, still eroding the base of the cliff today.

### Why the cutbanks keep moving

Sand, silt and unconsolidated gravel stand steeply when dry, but water weakens them. Spring runoff, heavy rain, groundwater seeping out of the face and the river undercutting the toe can all trigger **slumps and landslides**. Fresh scars and fallen trees along the base show that the slopes are still adjusting.

For your safety:

- Never walk to the edge at the top of a cutbank; the lip can be undercut.
- Do not climb or dig into the faces.
- Keep dogs and children back from unfenced edges.

Current river conditions are on our [rivers dashboard](https://princegeorgepulse.ca/dashboard/rivers/).

![Walkers on the LC Gunn Park trail on top of the Fraser River silt bluffs](https://princegeorgepulse-media.s3.ca-central-1.amazonaws.com/prince-george/guides/two-walkers-trail-lc-gunn-park-looking-over-efe0aa-1280.webp)

The LC Gunn Park trail runs along the top of the Fraser's silt bluffs. Photo: CPG1100, CC BY-SA 4.0 via Wikimedia Commons

## How the ice age shapes daily life

The glacial past is not just scenery. According to the geotour, the **sand and gravel under the bowl hold the aquifer** that feeds the city’s water wells, which is why protecting groundwater from spills matters so much here. Local quarries mine the same deposits for concrete and asphalt. The bowl also traps cold air and smoke during winter inversions, a big reason air quality can suffer on still days. See the [air quality dashboard](https://princegeorgepulse.ca/dashboard/air-quality/).

## Where to see it

| Place | What you will see |
| --- | --- |
| Forests for the World lookout, Cranbrook Hill | The whole bowl, the plateau and, on clear days, the Rockies and Cariboo Mountains |
| UNBC access road lookout | The bowl, Connaught Hill and both river valleys |
| Lheidli T’enneh Memorial Park | Silt bluffs across the Fraser |
| Heritage River Trail and Cottonwood Island Park | Nechako cutbanks and the modern floodplain |
| Foothills Boulevard near Freimuller Avenue | Rare exposed volcanic bedrock (watch traffic) |
| Eskers Provincial Park, northwest of the city | Winding gravel ridges left by rivers under the ice |

## Related reading

- [Geography and rivers of Prince George](https://princegeorgepulse.ca/explore/geography-and-rivers/)
- [Parks and trails](https://princegeorgepulse.ca/visit/parks-and-trails/)
- [Five walks along the rivers](https://princegeorgepulse.ca/articles/five-walks-along-the-rivers/)

## Common questions

**Why is Prince George in a bowl?**

After the last ice age, the Fraser and Nechako rivers cut down through tens of metres of glacial sand and gravel and swung back and forth where they meet. That erosion hollowed out a wide, flat-floored valley, the bowl, below the surrounding plateau.

**What are the cutbanks made of?**

Mostly layers of sand and gravel laid down by glacial meltwater, capped by a few metres of fine sand and silt deposited on the floor of Glacial Lake Prince George. Locals call them silt bluffs, but much of the height is actually sand and gravel.

**Are the cutbanks dangerous?**

Yes. They are loose, steep and actively eroding, and slumps and slides happen. Stay back from the edges at the top and do not climb the faces. Enjoy them from riverside trails and viewpoints.

**Where can I see evidence of the glacial lake?**

Look across the Fraser from Lheidli T’enneh Memorial Park at the bluffs, view the Nechako cutbanks from the Heritage River Trail and Cottonwood Island Park, and look over the whole bowl from the UNBC hill or the Forests for the World lookout.

## Sources

- [Geotour Guide for Prince George, British Columbia (GSC Open File 5559 / BCGS Geofile 2010-10)](https://mineralsed.ca/site/assets/files/3451/princegeorgegeotourguide.pdf)
- [Cutbanks (The Exploration Place)](https://theexplorationplace.com/project/cutbanks/)
- [Glaciolacustrine deposits (Wikipedia)](https://en.wikipedia.org/wiki/Glaciolacustrine_deposits)
- [Nechako Plateau (Wikipedia)](https://en.wikipedia.org/wiki/Nechako_Plateau)
- [Surficial geology, Nechako River, British Columbia (Natural Resources Canada)](https://osdp-psdo.canada.ca/dp/en/search/metadata/NRCAN-GEOSCAN-1-215892)

## Official links

- [The Exploration Place: Cutbanks project](https://theexplorationplace.com/project/cutbanks/)
- [Forests for the World (City of Prince George)](https://www.princegeorge.ca/parks-recreation/parks-trails/forests-world)
- [Lheidli T'enneh Memorial Park (City of Prince George)](https://www.princegeorge.ca/parks-recreation/parks-trails/lheidli-tenneh-memorial-park)

## On this page

- [The setting: a plateau split by two rivers](https://princegeorgepulse.ca/explore/glacial-lake-prince-george/#the-setting-a-plateau-split-by-two-rivers)
- [Step by step: how the bowl formed](https://princegeorgepulse.ca/explore/glacial-lake-prince-george/#step-by-step-how-the-bowl-formed)
- [The cutbanks up close](https://princegeorgepulse.ca/explore/glacial-lake-prince-george/#the-cutbanks-up-close)
- [How the ice age shapes daily life](https://princegeorgepulse.ca/explore/glacial-lake-prince-george/#how-the-ice-age-shapes-daily-life)
- [Where to see it](https://princegeorgepulse.ca/explore/glacial-lake-prince-george/#where-to-see-it)
- [Related reading](https://princegeorgepulse.ca/explore/glacial-lake-prince-george/#related-reading)

## Data

Machine-readable data behind this page, from the free PG Pulse API (https://princegeorgepulse.ca/developers/).

### Guide facts, FAQ and sources

Source: [PG Pulse guides (plain-language guides with links to official sources)](https://princegeorgepulse.ca/). Licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Updated 2026-09-30T00:00:00.000Z.
JSON: https://princegeorgepulse.ca/api/v1/guides/explore/glacial-lake-prince-george?fields=summary,faq,officialLinks,sources,updated

- **summary**: The ‘bowl’ is a broad valley carved into the Nechako Plateau where the Fraser and Nechako valleys merge., About 25,000 years ago an ice sheet roughly 2 km thick covered the Prince George area., As the ice melted, meltwater dumped thick sand and gravel, and a temporary lake, Glacial Lake Prince George, flooded the region., The rivers then cut down through those deposits, exposing the famous cutbanks and leaving flat ‘benches’ at several levels., The same buried gravels hold the aquifer that supplies the city’s drinking water.
- **updated**: 2026-09-30T00:00:00.000Z

#### faq

| q | a |
| --- | --- |
| Why is Prince George in a bowl? | After the last ice age, the Fraser and Nechako rivers cut down through tens of metres of glacial sand and gravel and swung back and forth where they meet. That… |
| What are the cutbanks made of? | Mostly layers of sand and gravel laid down by glacial meltwater, capped by a few metres of fine sand and silt deposited on the floor of Glacial Lake Prince Geo… |
| Are the cutbanks dangerous? | Yes. They are loose, steep and actively eroding, and slumps and slides happen. Stay back from the edges at the top and do not climb the faces. Enjoy them from … |
| Where can I see evidence of the glacial lake? | Look across the Fraser from Lheidli T’enneh Memorial Park at the bluffs, view the Nechako cutbanks from the Heritage River Trail and Cottonwood Island Park, an… |


#### officialLinks

| label | url |
| --- | --- |
| The Exploration Place: Cutbanks project | https://theexplorationplace.com/project/cutbanks/ |
| Forests for the World (City of Prince George) | https://www.princegeorge.ca/parks-recreation/parks-trails/forests-world |
| Lheidli T'enneh Memorial Park (City of Prince George) | https://www.princegeorge.ca/parks-recreation/parks-trails/lheidli-tenneh-memorial-park |


#### sources

| title | url |
| --- | --- |
| Geotour Guide for Prince George, British Columbia (GSC Open File 5559 / BCGS Geofile 2010-10) | https://mineralsed.ca/site/assets/files/3451/princegeorgegeotourguide.pdf |
| Cutbanks (The Exploration Place) | https://theexplorationplace.com/project/cutbanks/ |
| Glaciolacustrine deposits (Wikipedia) | https://en.wikipedia.org/wiki/Glaciolacustrine_deposits |
| Nechako Plateau (Wikipedia) | https://en.wikipedia.org/wiki/Nechako_Plateau |
| Surficial geology, Nechako River, British Columbia (Natural Resources Canada) | https://osdp-psdo.canada.ca/dp/en/search/metadata/NRCAN-GEOSCAN-1-215892 |

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