
Bouldering is a form of
rock climbing
Rock climbing is a climbing sports discipline that involves ascending climbing routes, routes consisting of natural rock in an outdoor environment, or on artificial resin climbing walls in a mostly indoor environment. Routes are documented in c ...
that is performed on small rock formations or
artificial rock walls without the use of ropes or
harnesses. While bouldering can be done without any equipment, most climbers use
climbing shoes to help secure footholds,
chalk
Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...
to keep their hands dry and to provide a firmer grip, and
bouldering mats to prevent injuries from falls. Unlike
free solo climbing, which is also performed without ropes, bouldering problems (the sequence of moves that a climber performs to complete the climb) are usually less than tall. Traverses, which are a form of boulder problem, require the climber to climb horizontally from one end to another.
Artificial climbing walls allow boulderers to climb indoors in areas without natural boulders.
Bouldering competitions take place in both indoor and outdoor settings.
The sport was originally a method of training for roped climbs and
mountaineering
Mountaineering, mountain climbing, or alpinism is a set of outdoor activities that involves ascending mountains. Mountaineering-related activities include traditional outdoor climbing, skiing, and traversing via ferratas that have become mounta ...
, so climbers could practice specific moves at a safe distance from the ground. Additionally, the sport served to build stamina and increase finger strength. During the 20th century, bouldering evolved into a separate discipline. Individual problems are assigned ratings based on difficulty. Although there have been various
rating systems A rating system can be any kind of rating applied to a certain application domain. They are often created using a rating scale.
Examples include:
* Motion picture content rating system
** Motion Picture Association film rating system
** Canadian ...
used throughout the history of bouldering, modern problems usually use either the V-scale or the
Fontainebleau
Fontainebleau ( , , ) is a Communes of France, commune in the Functional area (France), metropolitan area of Paris, France. It is located south-southeast of the Kilometre zero#France, centre of Paris. Fontainebleau is a Subprefectures in Franc ...
scale.
Outdoor bouldering
The characteristics of boulder problems depend largely on the type of rock being climbed. For example,
granite
Granite ( ) is a coarse-grained (phanerite, phaneritic) intrusive rock, intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly coo ...
often features long
cracks and
slabs while
sandstone
Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...
rocks are known for their steep overhangs and frequent horizontal breaks.
Limestone
Limestone is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...
and
volcanic rock
Volcanic rocks (often shortened to volcanics in scientific contexts) are rocks formed from lava erupted from a volcano. Like all rock types, the concept of volcanic rock is artificial, and in nature volcanic rocks grade into hypabyssal and me ...
are also used for bouldering.
There are many prominent bouldering areas throughout the United States, including
Hueco Tanks in Texas,
Mount Blue Sky in Colorado,
The Appalachian Mountains in The Eastern United States, and
The Buttermilks in
Bishop, California
Bishop (formerly Bishop Creek) is the only incorporated city in Inyo County, California, United States. It is located near the northern end of the Owens Valley within the Mojave Desert, at an elevation of . The city was named after Bishop Creek ...
.
Squamish, British Columbia is one of the most popular bouldering areas in Canada.
Europe is also home to a number of bouldering sites, such as
Fontainebleau
Fontainebleau ( , , ) is a Communes of France, commune in the Functional area (France), metropolitan area of Paris, France. It is located south-southeast of the Kilometre zero#France, centre of Paris. Fontainebleau is a Subprefectures in Franc ...
in France,
Meschia in Italy,
Albarracín
Albarracín () is a Spanish town, in the province of Teruel, part of the autonomous community of Aragon. According to the 2007 census (INE), the municipality had a population of 1075 inhabitants. Albarracín is the capital of the mountainous Si ...
in Spain, and various mountains throughout Switzerland.
Indoor bouldering
Artificial climbing walls are used to simulate boulder problems in an indoor environment, usually at
climbing gyms. These walls are constructed with wooden panels,
polymer
A polymer () is a chemical substance, substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeat unit, repeating subunits derived from one or more species of monomers. Due to their br ...
cement panels,
concrete
Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...
shells, or precast molds of actual rock walls.
Holds, usually made of
plastic
Plastics are a wide range of synthetic polymers, synthetic or Semisynthesis, semisynthetic materials composed primarily of Polymer, polymers. Their defining characteristic, Plasticity (physics), plasticity, allows them to be Injection moulding ...
, are then bolted onto the wall to create problems. Some problems use steep overhanging surfaces which force the climber to support much of their weight using their upper body strength.
Climbing gyms often feature multiple problems within the same section of wall. Historically, the most common method route-setters used to designate the intended problem was by placing colored tape next to each hold. For example, red tape would indicate one bouldering problem while green tape would be used to set a different problem in the same area. Indoor bouldering requires very little in terms of equipment: at minimum,
climbing shoes; at maximum, a chalk bag, chalk, a brush, and climbing shoes.
Grading
Bouldering problems are assigned numerical difficulty ratings by route-setters and climbers. The two most widely used rating systems are the V-scale and the Fontainebleau system.
The V-scale, which originated in the United States, is an open-ended rating system with higher numbers indicating a higher
degree of difficulty. The V1 rating indicates that a problem can be completed by a novice climber in good physical condition after several attempts. The scale begins at V0, and as of 2024, the highest V rating that has been assigned to a bouldering problem is V17.
Some climbing gyms also use a VB grade to indicate beginner problems.
The Fontainebleau scale follows a similar system, with each numerical grade divided into three ratings with the letters ''a'', ''b'', and ''c''. For example, Fontainebleau 7A roughly corresponds with V6, while Fontainebleau 7C+ is equivalent to V10. In both systems, grades are further differentiated by appending "+" to indicate a small increase in difficulty. Despite this level of specificity, ratings of individual problems are often controversial, as ability level is not the only factor that affects how difficult a problem may be for a particular climber. Height, arm length,
flexibility
Stiffness is the extent to which an object resists deformation in response to an applied force.
The complementary concept is flexibility or pliability: the more flexible an object is, the less stiff it is.
Calculations
The stiffness, k, of a ...
, and other body characteristics can also affect difficulty.
Highball bouldering
Highball bouldering is "a sub-discipline of bouldering in which climbers seek out tall, imposing lines to climb ropeless above crash pads." It may have begun in 1961 when
John Gill, without top-rope rehearsal or bouldering pads (which did not exist), bouldered a steep face on an granite spire called ''The Thimble''. In 2002
Jason Kehl completed the first highball at double-digit V-difficulty, called Evilution, a boulder in the Buttermilks of California, earning the grade of V12.

Important milestone ascents in this style include:
* ''Ambrosia'', V11, a boulder in Bishop, California, climbed by
Kevin Jorgeson in 2015.
*''Too Big to Flail,'' V10, another line in Bishop, California, climbed by
Alex Honnold in 2016.
*''The Process'', V16, a boulder in Bishop, California, first climbed by
Daniel Woods in 2015.
Competition bouldering

The
International Federation of Sport Climbing (IFSC) employs an indoor format (although competitions can also take place in an outdoor setting) that breaks the competition into three rounds: qualifications, semi-finals, and finals. The rounds feature different sets of four to six boulder problems, and each competitor has a fixed amount of time to attempt each problem. At the end of each round, competitors are ranked by the number of completed problems with ties settled by the total number of attempts taken to solve the problems.
Some competitions only permit climbers a fixed number of attempts at each problem with a timed rest period in between.
In an open-format competition, all climbers compete simultaneously, and are given a fixed amount of time to complete as many problems as possible. More points are awarded for more difficult problems, while points are deducted for multiple attempts on the same problem.
In 2012, the IFSC submitted a proposal to the
International Olympic Committee
The International Olympic Committee (IOC; , CIO) is the international, non-governmental, sports governing body of the modern Olympic Games. Founded in 1894 by Pierre de Coubertin and Demetrios Vikelas, it is based i ...
(IOC) to include
lead climbing in the
2020 Summer Olympics
The officially the and officially branded as were an international multi-sport event that was held from 23 July to 8 August 2021 in Tokyo, Japan, with some of the preliminary sporting events beginning on 21 July 2021. Tokyo ...
. The proposal was later revised to an "overall" competition, which would feature bouldering, lead climbing, and
speed climbing. In 2016, the
International Olympic Committee
The International Olympic Committee (IOC; , CIO) is the international, non-governmental, sports governing body of the modern Olympic Games. Founded in 1894 by Pierre de Coubertin and Demetrios Vikelas, it is based i ...
(IOC) officially approved climbing, along with four other sports, as an Olympic sport, based on their "impact on gender equality, the youth appeal of the sports and the legacy value of adding them to the Tokyo Games".
History
Modern bouldering
Modern recreational climbing began in the late 19th century in England, southeastern Germany, northern Italy, and France. Bouldering on the rocks of
Fontainbleau outside of Paris began in the late 1800s, with the first guidebook written by Maurice Martin in 1945. Bouldering as training or a recreational past-time began also in the late 1800s in England and perhaps elsewhere.
Oscar Eckenstein was an early proponent.
In the late 1950s,
John Gill, who is frequently called "the father of modern bouldering", combined
gymnastics
Gymnastics is a group of sport that includes physical exercises requiring Balance (ability), balance, Strength training, strength, Flexibility (anatomy), flexibility, agility, Motor coordination, coordination, artistry and endurance. The movem ...
with rock climbing, and felt that the best place to do that was on boulders or small outcrops. He developed a rating system that was closed-ended: B1 problems were as difficult as the most challenging roped routes of the time, B2 problems were more difficult, and B3 problems had been completed once. He also introduced
chalk
Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Ch ...
as a method of keeping the climber's hands dry, promoted a dynamic climbing style, and emphasized the importance of
strength training
Strength training, also known as weight training or resistance training, is exercise designed to improve physical strength. It is often associated with the lifting of Weightlifting, weights. It can also incorporate techniques such as bodyweigh ...
to complement skill. His 1969 article in the Journal of the American Alpine Club entitled "The Art of Bouldering" defines modern bouldering. As Gill improved in ability and influence, his ideas became the norm.
In the 1980s, two important training tools emerged. One important training tool was
bouldering mats, also referred to as "crash pads", which protected against injuries from falling and enabled boulderers to climb in areas that would have been too dangerous otherwise. The second important tool was indoor climbing walls, which helped spread the sport to areas without outdoor climbing and allowed serious climbers to train year-round. As the sport grew in popularity, new bouldering areas were developed throughout Europe and the United States, and more athletes began participating in bouldering competitions. The visibility of the sport greatly increased in the early 2000s, as
YouTube
YouTube is an American social media and online video sharing platform owned by Google. YouTube was founded on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim who were three former employees of PayPal. Headquartered in ...
videos and climbing
blog
A blog (a Clipping (morphology), truncation of "weblog") is an informational website consisting of discrete, often informal diary-style text entries also known as posts. Posts are typically displayed in Reverse chronology, reverse chronologic ...
s helped boulderers around the world to quickly learn techniques, find hard problems, and announce newly completed projects.
File:Gill_on_The_Scab_,_1963_,_The_Needles_of_the_Balck_Hills,_SD.jpg, John Gill on the Scab in the Needles of the Black Hills, 1963
File:Christian Core on Gioia.jpg, Christian Core on ''Gioia'' ( Varazze, ITA), first boulder in history, 2008
File:Midnight Lightning yosemite.jpg, Michael Rael Armas on Midnight Lightning, Camp 4 (Yosemite National Park
Yosemite National Park ( ) is a List of national parks of the United States, national park of the United States in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The p ...
, USA), one of the world's most famous bouldering problems
Notable ascents
Notable boulder climbs are chronicled by the climbing media to track progress in boulder climbing standards and levels of technical difficulty; in contrast, the hardest
traditional climbing routes tend to be of lower technical difficulty due to the additional burden of having to place protection during the course of the climb, and due to the lack of any possibility of using natural protection on the most extreme climbs.
As of November 2022, the world's hardest bouldering routes are ''
Burden of Dreams
''Burden of Dreams'' is a 1982 documentary film directed and produced by Les Blank.
Synopsis
The film is a making-of documentary about the chaotic production of Werner Herzog's 1982 film '' Fitzcarraldo''. It was filmed on location in the jun ...
'' by
Nalle Hukkataival and ''Return of the Sleepwalker'' by
Daniel Woods, both at proposed grades of . There are a number of routes with a confirmed climbing grade of , the first of which was ''Gioia'' by
Christian Core in 2008 (and confirmed by
Adam Ondra in 2011). As of December 2021, female climbers
Josune Bereziartu,
Ashima Shiraishi, and
Kaddi Lehmann have repeated boulder problems at the boulder grade. On 28 July 2023,
Katie Lamb became the first female climber to climb an -rated boulder by repeating ''Box Therapy'' at
Rocky Mountain National Park
Rocky Mountain National Park is a List of national parks of the United States, national park of the United States located approximately northwest of Denver in north-central Colorado, within the Front Range of the Rocky Mountains. The park is s ...
. However, after
Brooke Raboutou repeated the climb In October 2023, the boulder was ultimately downgraded to .
Equipment
Unlike other climbing sports, bouldering can be performed safely and effectively with very little equipment, an aspect which makes the discipline highly appealing, but opinions differ. While bouldering pioneer
John Sherman asserted that "The only gear really needed to go bouldering is boulders," others suggest the use of climbing shoes and a chalkbag – a small pouch where ground-up chalk is kept – as the bare minimum, and more experienced boulderers typically bring multiple pairs of climbing shoes, chalk, brushes, crash pads, and a skincare kit.
Climbing shoes have the most direct impact on performance. Besides protecting the climber's feet from rough surfaces, climbing shoes are designed to help the climber secure footholds. Climbing shoes typically fit much tighter than other athletic footwear and often curl the toes downwards to enable precise footwork. They are manufactured in a variety of different styles to perform in different situations. Stiffer shoes excel at securing small edges, whereas softer shoes provide greater sensitivity. The front of the shoe, called the "toe box", can be asymmetric, which performs well on overhanging rocks, or symmetric, which is better suited for vertical problems and
slabs.
To absorb sweat, most boulderers use
gymnastics chalk on their hands, stored in a chalk bag, which can be tied around the waist (also called sport climbing chalk bags), allowing the climber to reapply chalk during the climb. There are also versions of floor chalk bags (also called bouldering chalk bags), which are usually bigger than sport climbing chalk bags and are meant to be kept on the floor while climbing; this is because boulders do not usually have so many movements as to require chalking up more than once. Different sizes of
brushes are used to remove excess chalk and debris from boulders in between climbs; they are often attached to the end of a long straight object in order to reach higher holds. Crash pads, also referred to as
bouldering mats, are foam cushions placed on the ground to protect climbers from injury after falling.
Boulder problems are generally shorter than from ground to top. This makes the sport significantly safer than
free solo climbing, which is also performed without ropes, but with no upper limit on the height of the climb.
However, minor injuries are common in bouldering, particularly
sprained ankles and
wrists. To prevent injuries, boulderers position
crash pads near the boulder to provide a softer landing, as well as one or more
spotters to help redirect the climber towards the pads. Upon landing, boulderers employ falling techniques similar to those used in gymnastics: spreading the impact across the entire body to avoid
bone fracture
A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a ''c ...
s and positioning limbs to allow joints to move freely throughout the impact.
File:Quechua climbing shoes.jpg, A modern climbing shoe
File:Joshue Tree National Park - Manx Boulder - 6.jpg, Using spotters for safety
File:GIOVANNI BOULDERING.jpg, Using crash pads
Techniques
Although every type of rock climbing requires a high level of strength and technique, bouldering is the most dynamic form of the sport, requiring the highest level of power and placing considerable strain on the body. Training routines that strengthen fingers and forearms are useful in preventing injuries such as
tendonitis and ruptured ligaments. However, as with other forms of climbing, bouldering technique begins with proper footwork.
Leg muscles are significantly stronger than
arm muscles; thus, proficient boulderers use their arms to maintain balance and body positioning as much as possible, relying on their legs to push them up the rock. Boulderers also keep their arms straight with their shoulders engaged whenever feasible, allowing their bones to support their body weight rather than their muscles.
Bouldering movements are described as either "static" or "dynamic". Static movements are those that are performed slowly, with the climber's position controlled by maintaining contact on the boulder with the other three limbs. Dynamic movements use the climber's
momentum
In Newtonian mechanics, momentum (: momenta or momentums; more specifically linear momentum or translational momentum) is the product of the mass and velocity of an object. It is a vector quantity, possessing a magnitude and a direction. ...
to reach holds that would be difficult or impossible to secure statically, with an increased risk of falling if the movement is not performed accurately.
Environmental impact
Bouldering can damage vegetation that grows on rocks, such as
moss
Mosses are small, non-vascular plant, non-vascular flowerless plants in the taxonomic phylum, division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Wilhelm Philippe Schimper, Schimp. 1879) may also refer to the parent group bryo ...
and
lichen
A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...
s. This can occur as a result of the climber intentionally cleaning the boulder, or unintentionally from repeated use of handholds and footholds. Vegetation on the ground surrounding the boulder can also be damaged from overuse, particularly by climbers laying down crash pads.
Soil erosion
Soil erosion is the denudation or wearing away of the Topsoil, upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, Atmosphere of Ea ...
can occur when boulderers trample vegetation while hiking off of established trails, or when they unearth small rocks near the boulder in an effort to make the landing zone safer in case of a fall. Other environmental concerns include
littering, improperly disposed
feces
Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
, and
graffiti
Graffiti (singular ''graffiti'', or ''graffito'' only in graffiti archeology) is writing or drawings made on a wall or other surface, usually without permission and within public view. Graffiti ranges from simple written "monikers" to elabor ...
. These issues have caused some land managers to prohibit bouldering, as was the case in Tea Garden, a popular bouldering area in
Rocklands, South Africa.
See also
*
Competition climbing
Competition climbing is a form of regulated rock climbing, rock-climbing competition held indoor climbing, indoors on purpose-built artificial climbing walls (earlier versions were held on external natural rock surfaces). The three competition ...
*
Free solo climbing
*
Lead climbing
References
Works cited
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External links
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{{Extreme sports
Articles containing video clips
Types of climbing
Sports originating in France
Summer Olympic disciplines