The updated material below was posted 2/18/23.
Updated 2/5/2023 - The information below has been updated with new ratings for 144 non-technical routes up Sierra Nevada peaks, including coverage of an additional fifty-eight mountains. In addition, the ratings for twenty-two routes have been revised, with most of the revisions pertaining to the easiest routes up SPS peaks. All new and revised ratings are shown in red text. The two tables covering the official SPS Peaks List and Non-SPS High Sierra summits now provide Mountain Scrambler Ratings for 611 non-technical routes up 433 mountains in the Sierra Nevada, representing more than a 30% increase in coverage relative to the last updating of the tables in April 2020. The table for the SPS Peaks now provides Scrambler Ratings for the easiest route up each of the 247 mountains on the official SPS Peaks List. Also, Scrambler Ratings coverage now includes at least one route up each of the one-hundred mountains on the Vagmarken Club Sierra Crest List. All non-SPS High Sierra peaks covered by Scrambler Ratings are listed as summits on the GNIS (Geographic Names Information System) of the USGS or have been approved by the SPS as Sierra summits that qualify for the Andy Smatko Explorer Emblem.
The Mountain Scramblers Rating framework and two lists of ratings were first posted in November 2019. Based on an article in the April-June 2019 issue of The Sierra Echo, the summary Scrambler Ratings Definitions provided below explain the underlying criteria for the new framework for rating the difficulty of non-technical mountain scrambles and the relationship of the Mountain Scrambler ratings to the longstanding Yosemite Decimal System (YDS) ratings. The new ratings framework has benefited from some refinements over the past four years, reflecting comments and suggestions for SPS members and other scramblers of Sierra peaks.
During the most recent updating of the Scrambler Ratings, comparative examples of Scrambler Ratings were posted on the SPS Facebook page in order to elicit comments and suggestions on existing ratings. As in the past, SPS and other Sierra Nevada peak baggers are encouraged to offer additions and changes to the two lists of Scrambler Ratings for non-technical routes up mountains in the High Sierra. Please contact Phil at email@example.com with comments, suggestions, questions, additions and changes to the tables.
The first table now provides Mountain Scrambler Ratings and related Yosemite Decimal System (YDS) for 383 non-technical routes up SPS peaks, including the easiest route up each of the 247 mountains on the official SPS Peaks List. With the latest update, multiple non-technical routes are rated for 108 SPS peaks. (Scrambler Ratings SPS Peaks List.)
The second table for non-SPS High Sierra peaks now offers Mountain Scrambler Ratings and related YDS ratings for 186 peaks and 228 different non-technical routes, representing increases of 45% and 63%, respectively. (Scrambler Ratings for Non-SPS High Sierra Peaks.)
Definitions for Scrambler Ratings - PDF Copy
To distinguish the difficulty of non-technical mountain climbs more clearly, the ratings framework for mountain scramblers divides each of the four, non-technical Yosemite Decimal System (YDS) categories into three parts and expands the scope of the ratings. While the YDS ratings only address the difficulty of the hardest section of a route, Mountain Scrambler Ratings also consider the length of the most challenging segments and other factors distinguishing the severity of mountain hikes and scrambles. The framework for Mountain Scrambler Ratings was introduced in the April-June 2019 issue of The Sierra Echo in the article “Improving Ratings for Mountain Scramblers,” which was written by Philip S. Bates.
As with the YDS system, Mountain Scrambler Ratings are subjective, but they are based on a few objective variables that determine the severity of a route’s most difficult segments. The key variables include steepness and stability of terrain, which together are the major determinants of exposure to hazards such as the risk posed by the climber falling off steep rocks or loose rocks collapsing on the scrambler. Additional factors for cross-country travel and lower angle scrambling include the presence of other obstacles in the form of vegetation, waterways and snow*.
Reflecting the importance of terrain steepness, each Scrambler Rating category notes the maximum angle of slopes on a route, dividing the grade of terrain into five classifications: low angle (0-20 degrees); moderate angle (20-40 degrees); fairly steep angle (40-60 degrees); steep (60-75 degree) and very steep (75 degrees and above). Steepness can refer to either the angle of ascent or adjacent slopes of routes following narrow, exposed ridges (i.e., aretes).
Likewise, each rating definition mentions the nature and stability of the route’s more difficult terrain. Loose rock surfaces of scree, talus, boulders and fractured, crumbly rock can greatly increase the difficulty and hazards posed by a mountain route, varying with the steepness of the landscape. Terrain is referred to as stable when foot and hand placements are solid and unstable when hiking and scrambling movements can induce slips, slides and falls of rocks and when holds must be tested.
Bushwhacking and stream-crossings can increase the seriousness of mountain hikes and scrambles by creating more difficult, and at times dangerous, footing and by creating route-finding challenges. The difficulty posed by vegetation and water obstacles may vary seasonally with the density of foliage and water levels. Dangerous spring or early summer stream-crossings can seasonally raise the difficulty rating of a scramble.
In summary, for each Scrambler Rating category, the definition addresses the extent and challenges of any off-trail travel, the length and difficulty of any scrambling, the steepness, nature and stability of the terrain and the degree of exposure to hazards. The Scrambler Ratings only address the extent and stability of the most difficult class of rock encountered on a route; the ratings do not address the extent and stability of terrain of lower degrees of difficulty on the route. As in the case of YDS ratings, Scrambler Ratings do not assess seasonal and daily variations in the risks posed by the angle, quality and extent of any snow that may cover part of the route.
The definitions outlined below describe the key characteristics of each Scrambling Rating category. All Scrambler Ratings are preceded by an “S” notation for “Scrambling” to distinguish them from the closely related but not identical YDS ratings.
YDS CLASS 1 - Hiking on trails and easy cross-country travel with little risk.
S-1.0 Hands-in-pockets walking on well-maintained trails from start to finish, with minimal risk aside from mountain weather and the effects of altitude.
S-1.1 Hikes predominately on a mix of maintained and use trails, requiring virtually no route-finding skill and covering terrain that consists of stable, easy footing, no vegetation or water obstacles and low to moderate grades. Any off-trail hiking is for short distances over easy terrain. There is little risk aside from weather and altitude.
S-1.2 Intermediate to long distances of cross-country travel over terrain with stable footing and low to moderate grades, and in some cases the route may involve extensive vegetation and/or stream crossings that require backcountry route-finding skills for efficiency and safety. Risks are limited to navigation errors and hazards posed by stream-crossings, weather and altitude.
YDS CLASS 2 - Simple scrambling and rough cross-country travel on scree, talus and boulders, with minimal exposure and low to moderate risk.
S-2.0 Modest distances of rough cross-country travel on low angle scree and talus, with only short segments of easy scrambling on moderate angle, stable terrain. Route-finding is fairly straightforward, with no important vegetation or water obstacles, and minimal exposure to rock slides and falls. Only occasional use of hands is needed for balance. Risk of serious injury from falls and hazards is small.
S-2.1 Short to intermediate distances of rough cross-country travel on low angle scree, talus and boulders, with extensive, easy scrambling on moderate angle terrain that is predominately stable. Hands are often used for balance. Some route-finding skill is needed for efficient and safe travel across or around more difficult terrain, vegetation, stream-crossings and rockfall hazards. The risk of serious injury from slips and rockfalls is small to medium.
S-2.2 Intermediate to longer distances of rough cross-country travel with lengthy stretches of easy to medium difficulty scrambling on moderate to fairly steep angle scree, talus and boulders that are sometimes unstable. The use of hands is frequently required for balance and to test the stability of talus and boulders. Good route-finding skills are necessary for efficient and safe travel across or around more difficult terrain, vegetation or stream-crossings, and rockfall hazards. The risk of serious injury from falls or hazards is medium to significant.
YDS CLASS 3 - Moderate scrambling on steep, rocky terrain that requires handholds for upward movement and safety. Beginners may want a belay due to increased exposure and risk of serious injury.
S-3.0 Brief, medium difficulty to hard scrambling on fairly steep to steep angle, stable rock with medium to high exposure. Hard scrambling is limited to a small number of moves on steep and exposed rock. Hand and foot holds are large, secure and easy to find, requiring little climbing experience. Route finding is easy, with little potential for straying onto more difficult and dangerous terrain. Medium to significant risk of serious injury from falls or other hazards.
S-3.1 Short to intermediate length, hard scrambling on fairly steep to steep angle and predominately stable rock with high exposure. Hard scrambling is required for several short segments or an intermediate length of steep rock, which is highly exposed, but stable. Hand and foot holds are numerous, solid and easy to find, requiring limited climbing experience. Given the length and steepness of the scrambling, beginners may wish to use a rope to more safely manage the significant exposure and the challenges of down-climbing. Modest route-finding skills are necessary to avoid more difficult and dangerous terrain. Significant risk of serious injury from falls or other hazards.
S-3.2 Extensive, hard scrambling on fairly steep to steep angle and sometimes unstable rock with high to severe exposure. Hard scrambling is required for numerous short to intermediate segments or a long pitch of steep, highly exposed rock that at times may be unstable. Also included are short to intermediate length, hard scrambling with substantial, unstable rock hazards. Hand and foot holds are numerous and easy to find, but holds often need to be tested. Though only modest climbing skills are needed, some climbers may desire a rope due to the sustained nature, steepness and exposure of the hard scrambling segments, as well as the presence of unstable rocks and the challenges of down-climbing. Route-finding skill is needed to avoid more difficult terrain and minimize vulnerability to unstable rocks. A helmet may be advisable. Falls or hazards pose a high risk of serious injury or death.
YDS CLASS 4 - Difficult and exposed scrambling on very steep terrain where a rope is often advisable for safety, given the substantial risk of serious injury or death in the event of a fall.
S-4.0 Brief, very hard scrambling on extremely steep, stable rock with high to severe exposure. Very hard scrambling is limited to only a small number of climbing moves up a very short length of extremely steep rock with very high exposure. Holds are readily available and solid, but are smaller and more difficult to identify than on Class S-3 rock. Accordingly, some climbing skills are needed, a helmet is desirable, and a rope is useful for for belays and descent. A fall poses a high risk of serious injury or death.
S-4.1 Short to intermediate length, very hard scrambling on extremely steep and predominately stable rock with severe exposure. Very hard scrambling is required for several short segments or an intermediate length of climbing over extremely steep rock, which is severely exposed but stable. Holds are numerous and solid, but smaller and more difficult to find than on Class S-3 rock. The greater length of the very hard scrambling requires more commitment, thus making intermediate climbing and route-finding skills desirable. Many climbers will desire a helmet and a rope for belay and rappel. A fall poses a high risk of serious injury or death.
S-4.2 Extensive, very hard scrambling on extremely steep and sometimes unstable rock with severe exposure. Very hard scrambling is required for numerous short to intermediate segments or a long pitch of extremely steep, severely exposed rock that at times may be unstable. Also included are short to intermediate length, very hard scrambling with substantial, unstable rock hazards. Each hold should be tested and is smaller and harder to identify than on Class S-3 rock. The number and length of pitches of very hard scrambling require significant commitment and make intermediate climbing and route-finding skills desirable. Route-finding errors often lead to technical rock. Most climbers will desire a helmet and a rope for belay and descent. A fall poses a high risk of serious injury or death.
* The Scrambler Ratings coverage is for 246 SPS Peaks, plus one suspended peak, Pilot Knob (S). However, the coverage excludes Mount Starr King, which has no non-technical routes. Also, reader should note that the summit rocks entail technical climbing for three SPS Peaks: Mount Clarence King, Thunderbolt and The Hermit.
** Winter hikes and scrambles up mountains pose many challenges outside the scope of the Scrambling Ratings system. However, many Spring to Autumn scrambles cross snow slopes. Accordingly, the April-June 2019 Sierra Echo article “ Improving Ratings for Mountain Scramblers” addresses the difficulties and risks presented by snowfields and a simple framework is outlined for adjusting the ratings for such considerations.