A slopeside location-based social networking service came to five ski resorts this season, allowing skiers and boarders to track their Vail Resorts vertical feet, earn virtual ski pins and connect with friends. Called EpicMix, Vail Resorts rolled the system out to mountains in California and Colorado, covering 17,000 acres or about 70 square kilometers of terrain.The most important part of the system is the RFID lift ticket, which stores customers' ski passes and data. Vail Resorts CIO Robert Urwiler explained that when the resorts began using the passes in 2007 they chose the UHF version so it could be read from several meters. Not only did that mean increased convenience for skiers in having their passes read and verified, but it opened the door for programs like EpicMix.See EpicMix in action on the slopes of Vail Mountain.Before skiers sit down on a chair lift or gondola they pass through a metal structure called a gantry, off which four RFID readers hang, explained Mike Slone, Vail Resorts interactive director, speaking slopeside."Gantries are these metal structures of sorts that people don't typically notice, but as they ride a lift they go through these gantries and we scan them so we know where they're at on the mountain," Slone said. The gantries, some in very remote areas of the mountain, are connected through a Wi-Fi mesh network."From there the gantries then connect to a database and a Web app that allows us to calculate vertical feet and then we award digital ski pins for exploration on the mountain," said Slone, clad in a bright yellow jacket and sporting wide powder skis.The digital ski pins are of course a reference to physical pins that skiers collect from different mountains. With apr\u00e8s ski tales filled with bragging about double black diamond trails and knee deep powder, skiers and boarders can pull up their latest conquests on an iOS or Android device app or through the Web. EpicMix is similar to location-based social networking application FourSquare, but one way it differs is that manual check-ins are not required."It doesn't require that you have a mobile phone or that you get your mobile phone out or have a GPS device," he said. "You go about your day as you've always done; you ski, you have fun and then if you chose to you can log into your Epic Mix account."The data is updated within minutes of passing through a gantry.EpicMix is available at Vail, Beaver Creek, Breckenridge, Keystone and Heavenly. It will come to Northstar-at-Tahoe next season. Urwiler said that while Vail Resorts considered licensing the technology to other mountains, it eventually decided against it, keeping it as a competitive advantage.Slone said that in the first few months that the service was available some avid skiers earned several hundred thousand to a few million vertical feet. To put that in perspective, the typical vertical rise on a mountain in the western U.S. is 3,000 to 4,000 feet. Some of the pins are easy to earn, like the Mountain Division pin, which is awarded for a first visit to Vail. I tried the system out, and my most impressive pin was the Golden Feet pin, for covering 50,000 vertical feet (for the record I skied 66,267 feet in five days on the mountain.) There are more difficult pins to earn like the Conqueror pin, which is awarded for skiing every lift on a given mountain, sometimes a tricky task at a place like Vail where there are 31 lifts and 193 trails. Or there's the Smorgasbord pin for skiing all five resorts participating in EpicMix. Slone said there are 160 to 180 pins, with some being decommissioned and new ones being added frequently.EpicMix can also push updates to social networking sites like Facebook and Twitter, though Slone admits the integration needs a little work, saying that users should have finer-grain control of what's pushed. Currently users can enable or disable three types of updates: one that notifies friends of your first run of the day, one that tells them when you "level-up" and one that announces the new pins that you've earned. Even so, that meant that my Facebook wall had a long string of EpicMix posts, prompting one of my friends to comment, "Nick, you don't have to check in every time you get on a lift."Vail Resorts is touting Epic Mix as an on mountain improvement, likening it to installing a new ski lift. It hasn't yet wrapped much marketing around the system, but considering the way FourSquare has gone, third party promotions through EpicMix might not be far behind. As with any location tracking technology, privacy is a concern, but Slone said that there are options on the EpicMix site to turn sharing off. If privacy is a greater concern skiers can have the RFID chip removed from their pass altogether. He said that less than 10 people the entire 2010-2011 season have asked for their RFID chips to be removed.The idea for EpicMix came up about a year ago. By the time the snow had melted that year, Vail Resorts partnered with RFID vendor ODIN and created a proof-of-concept gantry that had a 99 percent read accuracy, according to Urwiler. From there, Vail Resorts began installing the hardware across its five ski resorts and rented data center space from ViaWest in Denver, racing to have everything in place for the season open.Both Urwiler and Slone agreed that one of the biggest challenges of the implementation was creating everything from scratch, including hardware like the gantries to back-end software to manage the data. The two credited Vail Resorts CEO Rob Katz with encouraging the interdepartmental cooperation needed to roll out the system along with the forward-thinking needed to get the project off the ground.It's not finished though. While Vail Resorts isn't ready to announce it and details were vague, photography could be added to the system next season, filling out its slogan of "Capture. Connect. Share."Nick Barber covers general technology news in both text and video for IDG News Service. E-mail him at Nick_Barber@idg.com and follow him on Twitter at @nickjb.