Alta is a unique place on earth and the foundation for its unique character begins with the Wasatch Fault.  The Wasatch Fault created the mountains that trapped the snow that formed the ice that made the glaciers that shaped the terrain.  This process continues today and it will continue for millions of years.  We’re all the better for it and it’s possible, just possible that on your next visit to Alta, High Rustler will be a little bit higher than before.

We hope you have enjoyed your journey through the geology of Alta.  If you have any questions or comments please contact us.  Thank you for your interest and we’ll see you at Alta.

The Park City resorts are dramatically different than Alta.  Located on the leeward side of the Wasatch Mountains, Park City ski resorts don’t receive nearly as much snow as Big or Little Cottonwood Canyons and show little evidence of glaciation.  The ski slopes have a convex shape and there are no high surrounding peaks to protect the runs from winter sunshine.

Each ski area in the Wasatch mountains has it’s own distinctive character and the geologic history of each area strongly influences that character.  Brighton shares many similarities with Albion Basin.  Brighton was the source of the trunk glacier that flowed down Big Cottonwood Canyon.  Because of this, there is a lot of gentle terrain at Brighton.  Brighton and Solitude are located on the leeward side of the Wasatch Mountains ridge line.  As a result they do not get the snow totals of Little Cottonwood Canyon and received less snow during the glacial period.  Less snow means less ice.  Less ice means less spectacular scenery and terrain, particularly on the eastern sides of Big Cottonwood Canyon.

The High Traverse accesses Greeley Bowl and Greeley Hill, High Rustler, Eagles Nest and other steep terrain.  Greeley Bowl and Greeley Hill have the same geologic profile as most of the Back Side (see Back Side Description).  Along the way The High Traverse leads to Race Course, Sunspot, West Rustler, Stonecrusher and others.  Each of these runs experiences the east profile of the Collins Gulch U-shaped valley, beginning below the Ophir Shale.  Like all of these runs at Alta the farther down you go, the easier they get.  The High Traverse is not a specific topographic feature, but represents the highest line that can be skied from the top of the Collins lift to the pass leading into Greeley Bowl.  It lies just below the vertical cliffs of the Ophir Shale.

Racecourse follows part of the U-shaped valley on the southeast side of Collins Gulch.  It is in the transition zone between the valley and the glacial headwall and, as a result, is unusually steep.  The slope is concave and northwest facing and snow quality is excellent.

The Transfer Tow follows the line of the trunk glacier directly down Little Cottonwood Canyon.  Because of the erosional power of the ice here, the valley floor is nearly completely smooth with only a slight gradient down canyon.  This run wasn’t built for excitement but is the perfect slope for first time skiers to get used to the sensation of gliding without having to worry about picking up too much speed.

Eagles Nest was formed by a small pocket of snow and ice that accumulated and carved out the beginnings of a cirque.  The cirque was not very long lived however and didn’t develop many of the definitive characteristics.  The underlying rocks are limestones, so there are lots of cliffs and the terrain is steep.  Once out of the narrow exit of the nest you ski the lower part of the Little Cottonwood Canyon U-shaped valley which becomes progressively gentler.  The steep north-facing slope angle insures outstanding snow quality throughout most of the season.

At Supreme Bowl snow and ice hung in the deep shade formed by the limestone and marble cliffs long after it had melted away from many less protected areas at Alta.  As a result a steep-sided cirque formed in the cliff-forming limestones.  The long run-out at the bottom toward the Supreme Chair loading station follows the line of the trunk glacier.

The Crooked Mile was carved by the trunk glacier in Albion Basin.  As a result the Crooked Mile is a smooth gentle run with little variability in terrain.  Underlying rocks are the Alta Stock which forms rounded outcrops.  There are incremental changes in inclination on this run that makes it an excellent teaching hill for advanced-beginners and intermediate skiers.

The Devil’s Elbow is one of Alta’s most popular intermediate runs because of the consistent slope and wide trails.  These characteristics are the result of glacial smoothing and polishing of the Tintic Quartzite.  Most of the beds of the Tintic Quartzite dip about 25 degrees east in this area resulting in a topographic dip-slope situation, which adds to the generally uniform gradient in the area.

Catherine’s Area is a complete tributary glacial valley that flowed into Albion Basin.  It has all of the glacial features common to this environment, a broad cirque, a U-shaped valley, broad flat and distinct hanging valley just east of the Supreme Chair Lift.  Catherine’s area is like entering into a separate ski area with many of the characteristics of the rest of Alta, but on a smaller scale.  These characteristics offer a variety of skiing terrain.   The north side of Catherine’s bowl is underlain by the Alta Stock;  the south side by marble and limestone.

Glory Hole is a small steep-sided cirque cut into the Tintic Quartzite where ice remained long after it had melted elsewhere in much of Albion Basin.  Glory Hole Gulley was initially carved by run-off from the cirque glacier and is now occupied by a summer creek.

Corkscrew follows a stream channel that cut into the Collins Gulch hanging valley after the ice had melted.  This channel represents about 6,000 years of stream erosion.  Alta has widened the run somewhat to accommodate more skier traffic.  Corkscrew Gulley is the same stream channel cutting through gentle terrain at the bottom of the Collins Gulch U-shaped valley.  It forms a spectacular natural half pipe when there is adequate snow.

At Collins Face you have the experience of skiing over a hanging valley that has not been significantly affected by post glacial erosion.  The result is an abrupt steepening of pitch from the gentle slope of the Meadow above and a broad run-out into the valley of Little Cottonwood Canyon at the bottom.

At Stonecrusher you ski down a chute that transects all of the eastern profile of the Collins Gulch U-shaped valley from the base of the Ophir Shale cliffs to the valley bottom.  Like many of the runs at Alta it starts out steep and gradually flattens out toward the bottom of the valley.

The Back Side is the west side of the Albion Basin U-shaped valley.  Runs typically begin steeply (the High Notch and Eddy’s High Nowhere) and become gentler below.  The rocks exposed at the top of the Back Side are nearly vertical beds of the Cambrian Ophir Shale.  Three principle traverses access the Back Side; the High Notch Traverse, the High Traverse and Yellow Trail, giving the skier various options on steepness and degree of difficulty.

About three quarters of the way down the back side, the pitch of the slope steepens again.  This is probably the result of a younger glacial event, the Pinedale Glaciation, carving a smaller U-shaped valley within Albion Basin.  Susie’s trees has the same profile but with abundant evergreens which help snow quality and improve visibility during storms or on flat light days.

There are various ways to exit the back side.  Two challenging routes are Glitch and Glatch which follow narrow post-glacial stream channels that cut into the smooth glacial profile.

The cliffs of Devils Castle are made up of limestones.  These limestones are severely fractured and if you look carefully you’ll see that there are outcrops along the face of the Castle that appear to be hanging on precariously.  Several thousand years ago the face of Devil’s Caste fell off in an enormous, catastrophic, debris slide.  Huge boulders from this event can be traced through the woods.   You can see these boulders all the way down the Cecret chair and as far as Alf’s.  They make popular jumps, particularly at the base of the apron.  The rock debris collecting on the apron today is a slower continuation of this process, fueled by the freezing and thawing of water in the fractured limestones.  

The near vertical faces of Devil’s Castle and Sugarloaf Peak provide shade throughout most of the winter to an enormous area of moderately difficult ski terrain and like Ballroom, the area maintains excellent snow quality throughout.

Ballroom is a broad cirque, where ice collected and remained for thousands of years.  Above it are the cliffs of the Mt. Baldy headwall.  The cirque has a classic bowl shape.  Slopes are concave with the steepness of the slope increasing with altitude.  There are three separate traverse entrances into Ballroom allowing the skier to select an appropriate pitch for their ability.  The maximum ice level was probably only slightly above the upper traverse line.  The Baldy headwall keeps Ballroom in the shade through most of the winter maintaining outstanding snow quality during breaks in snow storms.

The Main Chute is a steeper version of Gunsight.  This challenging run is formed by the Gunsight fracture system cutting through the glacial headwall formed in the Tintic Quartzite at the head of the Collins Gulch glacier and the Ballroom Cirque.  The fracture is an effective snow trap, just wide enough to get your skis around.  This is all headwall and there is little flattening of the chute until you get near the bottom and enter the Ballroom cirque.

A northeast-trending structure cuts through the Ophir Shale allowing a narrow entry way to one of the finest snow traps on the mountain.  As you ski down Gunsight you ski down one of the fractures that hosted silver mineralization in the Little Cottonwood mining district.  This fracture cuts through the Albion Basin U-shaped valley and with each turn the run gets easier until it flattens out on a broad fen above the willows.  The depression caused by this fracture leaves a prominent ridge on the south side of the run, which shelters it from sunshine.

At the base of Gunsight if you continue straight down the hill on the north side of Susie’s Trees you’ll ski down a narrow post-glacial gulley carved by a creek.  If you stay to the left on Greeley Hill you’ll enjoy a smooth glacier polished slope.  Before you start down from the top of Gunsight, take a moment and look over at the Main Chute on Mount Baldy and see how the two runs line up.