Category Archives: glaciation

A Glacial Moraine in the Rio en Medio Watershed

It’s funny how you can walk over something for years without realizing its significance. I’ve headed off for hikes many times from the Ski Santa Fe parking area without giving a second thought about what it might be built on. I’ve picked my way gingerly down the Rio en Medio Trail, which connects with the Winsor Trail just south of this parking area, without wondering just why it is so steep and stony until you get to that first lovely meadow.

The top of the Rio en Medio Trail, at its intersection with Winsor Trail

The top of the Rio en Medio Trail, at its intersection with Winsor Trail

I’ve remarked on the extensive blowdowns near the Winsor-Rio en Medio Trail intersection with the only thought that there must have been a hell of a storm here once upon a time:

Part of a forest blow down along Winsor Trail

Part of a forest blowdown along Winsor Trail

It wasn’t until I hiked up the Winsor Trail from the south that the apple finally fell on my head. I was looking for the first outcroppings of gneiss that I fully expected to find somewhere along the way to the parking area, when I realized I was climbing up a very steep pile of crudely-rounded boulders instead of bedrock. Something that looked just like glacial moraine.

Now it’s not like we don’t have obvious evidence of alpine glaciation in the Santa Fe Range. This image of the north side of the Lake Peak massif, on which Ski Santa Fe is situated, shows a textbook example of a cirque, with a tarn – Nambe Lake – right where it should be, and a steep terminal moraine damming the U-shaped valley just below the lake:

Lake Peak from the north. Click on image to enlarge.

Lake Peak from the north. Click on image to enlarge.

When you swivel your view toward Santa Fe, however, you can see how different the west side of the mountain, where the ski runs are cut, is from the north and east sides:

Lake Peak showing Ski Santa fe

Lake Peak showing Ski Santa Fe. Click on the image to enlarge.

I never expected to see evidence of glaciation in Aspen Basin, which holds Ski Santa Fe, or Big Tesuque, the aspen-covered watershed of Tesuque Creek just beyond. Nevertheless, if you look carefully at this image of the ski area, you’ll see an odd little tongue protruding down from the parking area to the meadow at the bottom:

The parking area of Ski Santa Fe with a tongue of forested moraine below. Click on the image to enlarge.

The parking area of Ski Santa Fe with a tongue of forested moraine below. Click on the image to enlarge.

It’s this area that has all the anomalous features that suddenly fall into place when you realize what you’re hiking on. Groves of trees rooted in loose boulders rather than bedrock. Steep slopes studded with rocks that range from fist to room size:

Looking up from the Rio en Medio Trail

Looking up from the Rio en Medio Trail

A merry little stream that cascades without pause from rock to rock:

Cascades along the Rio en Medio

Cascades along the Rio en Medio

Rocks of a kind that could only have come from the ridges far above:

A migmatite carried down from Ravens Ridge

A migmatite carried down from Ravens Ridge

Even something that looks suspiciously like a glacial erratic:

A boulder perched among blown-down trees

A boulder perched among blown-down trees

Plus – for what it’s worth – the forest here has an attractive, but hard to define quality I associate with glacial country. Raked slopes, sculpturally-placed boulders, the sound of falling water – something. All I know is that this is one of my favorite places to come and find a rock to sit on, under the tall spruce, when I need a retreat from our civilized world. It’s nice to think that the ice did a little creative work on my side of the mountain. And a pleasure to think that it took me quite awhile to discover that fact.