There is no Matterhorn at Alta.  The Pfeifferhorn, a smaller version of its famous cousin was formed at the head of Maybird Canyon five miles west of Alta.  Glaciers had begun carving away at the sides of Sugarloaf Peak, forming a pyramid shape but had not eroded it to a point.
    
The prominent surface features created in the glacial environment, cirques, U-shaped valleys, hanging valleys and headwalls are concave in shape.  Concave slopes are very steep at the top, in some cases nearly vertical and become gentler towards the bottom, ending in long flat run-outs.  This is good for skiing because it gives the skier a variety of slope options; the higher you enter the slope, the more demanding the terrain.  The traverses at Alta access the ski slopes at different elevations giving the skier this option.  But the concave shape is also critical in preserving snow quality.  All of the headwalls above the cirques at Alta are north facing.  As a result, the ski slopes beneath Devils Castle, Sugarloaf Peak and Mt. Baldy stay in the shade during much of the ski season.  This keeps the snow cold, maintaining outstanding, soft, snow quality even during long periods between storms  

The same is true in the north facing, concave slopes on the south side of Little Cottonwood Canyon.  High Rustler, Eagles Nest, North Rustler, Collins Face, Bear Paw, and Westward Ho are all examples of steep, north facing concave slopes with excellent snow quality throughout most of the ski season.

The mouth of Little Cottonwood Canyon is littered with enormous boulders of granodiorite and granite sitting on metamorphic bedrock that is over a billion years old.  These boulders, called glacial erratics, were transported down the canyon by the ice and left behind when it melted.

The Little Cottonwood Glacier lateral moraine is well preserved on the south edge of the mouth of Little Cottonwood Canyon.  The terminal moraine was eroded away by waves from Lake Bonneville, a huge fresh water lake that filled the Salt Lake Valley after the ice melted.  The Great Salt Lake is an evaporite, a small salty remnant of this lake.  The lake is salty because heat evaporates water but not salt.

Smaller glaciers spilled into the trunk glacier from the south. Peruvian Gulch and Gad Valley glaciers entered from canyons at Snowbird. White Pine, Red Pine, Maybird and Hogum Canyons’ glaciers entered farther below.

The trunk glacier roared down Little Cottonwood Canyon, carving out the enormous U-shaped valley, removing 300-400 feet of rock along the sides of the old valley.

A second cirque formed in Ballroom at the base of Mount Baldy.  A near vertical headwall formed on the north face of Mount Baldy.  A tributary glacier carved its way down Collins Gulch, spilling into the trunk glacier in Little Cottonwood Canyon in a dramatic ice fall.  A hanging valley was left behind when the ice melted, now occupied by Corkscrew, Nina’s Curve, Shuss Gulley and Collins Face.  A knife edge ridge formed on the ridge in the Ophir Shale between Collins Gulch and Albion Basin.

Albion Basin was carved into a broad, smooth U-shaped valley and major undulations in the valley bottom were smoothed.

A vertical headwall was formed in Devil’s Castle and Sugarloaf Peak.  Devils Castle is also a knife edge ridge (arête) formed by the Albion glacier and a glacier in the adjacent valley to the south.  This was the head wall of the trunk glacier that occupied all of Albion Basin, made the turn into Little Cottonwood Canyon and eventually flowed to the Salt Lake Valley.

Assuming that Alta and Little Cottonwood Canyon were recently glaciated we should expect to see most or all of the glacial features described above.  Indeed we do.

The glaciers first formed as a cluster of cirques in upper Albion Basin.  These cirques began at Cecret Lake, Glory Hole, Sugar Bowl and Catherine’s Bowl and gradually coalesced until all of upper Albion Basin became a cirque-filled ice field.

A second photo from the western Alaska Range shows additional erosional features common to glaciers.  Between two glaciated valleys a knife edge ridge is often formed called an arête.  Where a mountain peak is surrounded by glaciers on all sides a pyramid-shaped horn is formed; the Matterhorn in Switzerland is the most famous example of this. 

A large glacier occupying a valley and beginning at the headwaters of that valley is referred to as a trunk glacier.  Smaller glaciers, sourced by smaller drainages, will enter the trunk glacier from the side.  Often these smaller glaciers will cascade into the trunk glacier over an ice fall.  When these glaciers melt they will leave behind U-shaped valleys and a steep hanging valley where the ice fall occurred.

It is difficult to fathom the erosional power of a glacier.  At its maximum extent, the glacier that occupied Little Cottonwood Canyon was over twelve miles long, one to two miles wide with a thickness of 1,000-2,000’ of ice.  A typical rate of movement along this glacier would be 5 to 10 feet/day, however; a surging glacier can travel in excess of 100 feet/day.  Glaciers of this scale remove hundreds of feet of bedrock from the bottom and sides of a stream valley.  They also smooth out irregularities in the valley bottom forming a consistent gradient.

On the north side of Mt. Hesperus there is a small active glacier.  This glacier is unusual in that the entire glacial system from hanging wall to terminus can be observed in one photograph and the glacier displays most of the major physiographic features formed in this environment.

The source area of the glacier is a rounded bowl, referred to as a cirque.  The cirque has near vertical headwalls on three sides but is flat or slightly inclined at the mouth.  Prior to glaciation the cirque was probably nothing more than a gentle depression on the north facing mountain slope.  Snow accumulated in this depression and as the glacier evolved, the movement of the ice carved out the circular shape. 

From the cirque the ice flows into a valley where it carved out a U-shaped valley with steep sides and a flat bottom.  This shape is distinguished from a V-shaped valley carved out by a river or stream. 

The glacier in this photo is receding, as are nearly all glaciers in North America.  As the glacier melts a huge debris pile is left behind along the sides of the glacier (lateral moraine) and at its terminus (terminal moraine).  The height of the moraine defines the maximum height and advance of the glacier.

Ancient glacial features are interpreted by comparing them with glacial features formed in current active glaciers.  Mount Hesperus is a horn in the Revelation Mountains in western Alaska.

The Wisconsin Glaciation, occurred in North America between 5,000-65,000 years before present.  The last major glacial event peaked about 16,000 years ago.  In eastern and central North America enormous continental glaciers scoured the landscape at this time.  In much of the west, alpine glaciers formed in the higher mountain ranges.
    
Alpine glaciers form when winter snowfall exceeds summer melt.  Over time snow accumulates and is compressed into ice.  Eventually gravity pulls the ice down mountain valleys and this mechanism continues so long as the snow supply exceeds snow melt.

Two factors are required for the formation of glaciers, cold temperatures and precipitation.  One factor is not necessarily more important than the other, but you have to have both to form ice.  For example, the southernmost glaciers in North America are found in the northern Sierra Nevada Mountains of California, not because it’s particularly cold there, but because it’s particularly wet.  In contrast, Alaska’s Brooks Range, the northernmost mountain range in the United States, has no glaciers at all, because it’s too dry.

In the Wasatch Mountains today snow does not accumulate from year to year.  Occasionally a small butterfly-shaped patch of snow will survive at the base of Devil’s Castle through the summer months.  Glaciers will only return to the Wasatch Mountains if there is a significant decrease in temperature (4-5 degrees Fahrenheit), a significant increase in precipitation (+30%) or a combination of both.

The Wisconsin Glaciation, occurred in North America between 5,000-65,000 years before present.  The last major glacial event peaked about 16,000 years ago.  In eastern and central North America enormous continental glaciers scoured the landscape at this time.  In much of the west, alpine glaciers formed in the higher mountain ranges.
    
Alpine glaciers form when winter snowfall exceeds summer melt.  Over time snow accumulates and is compressed into ice.  Eventually gravity pulls the ice down mountain valleys and this mechanism continues so long as the snow supply exceeds snow melt.

Two factors are required for the formation of glaciers, cold temperatures and precipitation.  One factor is not necessarily more important than the other, but you have to have both to form ice.  For example, the southernmost glaciers in North America are found in the northern Sierra Nevada Mountains of California, not because it’s particularly cold there, but because it’s particularly wet.  In contrast, Alaska’s Brooks Range, the northernmost mountain range in the United States, has no glaciers at all, because it’s too dry.

In the Wasatch Mountains today snow does not accumulate from year to year.  Occasionally a small butterfly-shaped patch of snow will survive at the base of Devil’s Castle through the summer months.  Glaciers will only return to the Wasatch Mountains if there is a significant decrease in temperature (4-5 degrees Fahrenheit), a significant increase in precipitation (+30%) or a combination of both.