The Phoenix Rock Gym first opened its doors August 15, 1992. Zipping time back 30 years we find Paul Diefenderfer (Dief) climbing at one of his favorite crags, Pinnacle Peak. Dief is approached by a man who is asking the rock climbers on how much would they pay to climb at a indoor rock gym. The man was thinking of opening a climbing gym somewhere along the Salt River. Dief replied back saying $2.00 since that would calculate out correctly with having a one month membership. The guy thought that was absurd. At the same time Dief thought it would be weird to have a rock gym, I mean, who wants to climb indoors anyways? In 1991 Paul Diefenderfer went to San Francisco for a American Alpine Club meeting where the Access Fund split off from the AAC. While there, Sam Davidson took Dief to a climbing gym named City Rock in the San Francisco area. It was Dief personally climbing indoors at City Rock that gave Dief the vision to create his own rock gym in Arizona. So he partnered with friend Eric Ramsey and began building. Dief and Eric both contributed $10,000 each, which started the gym which was located 2810 S. Roosevelt road in Tempe.
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The Phoenix Rock Gym logo was designed and created by Eric Ramsey
The idea for the construction of the gym was to build the gym phase by phase. As more monies came in, the monies would be used to build more walls in the gym which was a process that kept them out of debt. They leased a section of a warehouse building that was owned by Waxie janitorial supplies in Tempe, purchased a ton of plywood, and began building a long canyon of 24’ tall walls. After the gym was opened to the public, the gym remained closed on Wednesdays which became the main construction day to get more of the climbing walls built. The gym was built by Dief and Eric, and the painting on the walls had a Arizona theme to it. ​
By 1993 the gym had 36 top ropes and there was 8000 square feet of climbing available. The bouldering area was simple “T-Shaped” flat walls which were used as a warm up area for the gym top ropes. Jim Waugh was the main course setter where Jim also started the Phoenix Rock Gym climbing team. The climbing team eventually stopped when Jim was chosen to be the director of the climbing in the ESPN X-Games in late 1995. When Jim left, Joe Czerwinski took over the lead course setter position. Sometime in 1996 the bouldering area was rebuilt by Chris Raypole into a more modern bouldering area which actually had marked boulder problems for climbers to be challenged with. Also eventually a lead area was built in the far back of the gym which brought the gym up to 10,000 square feet of climbing by March 1997.
Eric Ramsey and Paul Diefenderfer
At the time the Phoenix Rock Gym first opened, Dief was the president of the Arizona Mountaineering Club. Dief thought to himself that this indoor climbing will never be as popular as the outdoor climbing, so he was worried if his investment in building a gym would ever pay off. There were a few other gyms already opened in the USA, but at the time the Phoenix Rock gym opened, the PRG was in a 4 way tie for the 6th rock gym to open in the USA. Definitely the Phoenix Rock Gym was the first rock gym to open in Arizona, and following very close by is the Rocks & Ropes gym in Tucson, opening December 1992. Dief’s quote for his first gym, “When we were kids, we all climbed.” “Most people grow up, and that’s a big mistake.” The General managers through the 8 years of the PRG Roosevelt location were:  Chris Pomeroy, Eric Eaglestun, April Prestwich, and Janette Lisco.
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Phoenix Gazette 7/1/1994
AZ Republic 1/20/1993
In 1997 a building was placed onto the market that Dief was interested in. He worked with the Realtors but could not lock in the ownership of the building. But eventually the building once again was placed onto the market and Dief once again showed interest. The overall problem was that there was a 10 year lease signed for the leased warehouse part of the Waxie building, but just by coincidence Waxie was expanding their business and easily let Dief out of the original lease allowing Dief to move the Phoenix Rock Gym into a new building. ​
AZ Republic 1/24/2001
The location was perfect being only a half mile away from Arizona State University. Dief bought out his partner Eric Ramsey’s half of the gym allowing Dief to completely own the gym. The new location is where the PRG is presently located, 1353 E. University Dr. A lot of quick welding and another ton of plywood later and the gym opened only having the lower portion of the bouldering completed, and the lead area was still in the process of being built. Dief and Chris Raypole hastily welded up the framework for the climbing walls, eventually assisted by a few other helpers Derek Underhill and Chris Foncannon. The new location of the Phoenix Rock Gym opened December 4, 2000. Joe Czerwinski was the lead coursetter where in August 2001 that Flying Zebra guy Marty Karabin was hired as Joe’s course setter helper. ​
Anna Marsolo assisted Dief in the painting of the gym which was many gallons of paint put on the walls in a non-uniform manner. Kinda like splatter painting. It looked artistic but also looked very rushed getting some form of paint chaos onto the walls. Anna added her Arizona theme touches which tied all of the canyons of the gym together. Joe went to work at the new Scottsdale rock gym AZ On The Rocks in 1993 which put Marty into the lead course setting role. But since Marty was already doing many other tasks besides course setting, Marty’s title became “Director of Vertical Entertainment.” Jeremy Cox became the Lead course setter in September 2017. The upstairs bouldering area began being built by Chris Raypole late 2006/early 2007 where the grand opening of the upstairs bouldering area was in the first Thrash & Dangle competition which was held August 18, 2007. Once the upstairs bouldering area was completed, that brought the PRG to 17,000 square feet of climbing in the building. Through the years, 10 Thrash & Dangle competitions were held at the gym, and two bouldering competitions named the Struggle Bus. The gym also hosted many USA Climbing ABS and SCS competitions for the youth climbing teams. ​
In 2004 Dief built metal stairs which led to a second floor area located above the bathrooms. The Over The Crux climbing store owned by Daniel Arlitt and Shelley Windsor moved into the space which added more energy to the gym. The Over the Crux store closed early 2006. Since the space was available, Marty decided to start a climbing store but first had Dief construct a roof over the store, and also a rolling ladder feature. Marty opened the AZ Cliff Hanger store October 12, 2006 and it was created to look somewhat like a old mining building. The space is fantastic as it overlooks the entire gym. Due to the 2008 recession and Marty breaking his leg in 2009, the store closed June 6, 2010. Then the TUFA Climbing Store owned by Scott McKinney moved into the space October 2010, and then closed its business in 2012. The upstairs space remained unoccupied until 2015 when it was transformed into a lounge and Marty’s, Karabin Climbing Museum, filled the space with historic gear displays which is still present today.
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Once Chris Raypole completed building the upstairs bouldering area, Chris in 2008-2009 started repainting the gym with amazing pieces of art. Chris repainted all of the gym climbing surfaces, except for the Cracks Wall and Lead Area. In 2016 Luke Wyssmann, who painted art pieces all over the gym especially on the bathroom doors, took on the task of repainting the Upstairs Bouldering Area, the Downstairs Bouldering Area, then the entire Lead Area. Luke transformed the Lead Area into a amazing space scene filled with creative space art characters. In 2016 the Dr. Seuss style huge mural was painted by Marty Karabin, Stephie Ruiz, Luke Wyssmann, and Katherine Martin. In 2019 Marty and Steph repainted the Heuco Canyon bringing it up to a more modern rock gym look. Jeremy Cox assisted with the project with the unending amount of patching and grinding that was needed to be done before the new paint was put in place. Then in March 2020 when suddenly the world got hit by the Covid 19 virus, the gym was forced to close for two months. During the closure Marty and Stephie went into painting mode once again repainting the Flake Feature, the Tower and the Lower Bouldering Area. And also adding additional smaller paintings around the gym. 
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Hueco Canyon 2000 - 2009
Hueco Canyon 2009 - 2019
Hueco Canyon 2019 to present
Since the University PRG location first opened, there have only been four General Managers over the last 20 years. Janette Lisco, Michelle Aubert, Erin Orwig, and Jaime Gangi. Over the years these managers kept the positive energy flowing to the customers, and continually introduced new ideas and gym operations. Jeremy Cox started a successful youth climbing team in March 2009 named Team Thrashers, which in 2012 the name was changed to the Rock Phenoms. The team coaches produced many amazing climbers over the years and still are busy teaching kids how to crush to this day! The many work out items around the gym were brought in by Jeremy. Jeremy also built many of the book case cubbies, seating cubbies and campus items in the gym. The climbing team room under the stairs leading to the Upper Bouldering area was built by Marty, with some welding by Justin Wagner, and painted by Jeremy. Justin also created and put in most of the pull up bars, and other welding projects around the gym. 


For me, Marty, I have been with the Phoenix Rock Gym for 20 years now, and it has been really cool to watch this gym continually grow. The amazing artists I have worked with have inspired me to dig deeper in my own creations. The many employees that the gym has had and has are great to work with. The 1.6 million visits of cheerful customers that have climbed at the gym have raised my personal psyche to climb stronger than I have ever climbed. It is great to have a place as unique as the Phoenix Rock Gym, which allows me to escape society’s suggestive daily demands. I can be who I want to be at the Phoenix Rock Gym since the kid in me shines through the most, when I am climbing!!! Over the last 30 years the Phoenix Rock Gym has received dozens of awards showing it is the best indoor place to rock climb in the valley!!!
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