Poland was represented by two groups of Highlanders from Chicago area in 2007.
Siumni is a Highlander's dancing and music group. The group was created about 7 years ago in Chicago. Once a year they get together in summer during Watra (correct pronounciation: Vatra). One can see some photographs from Siumni's watra. Watrais a highlander's watch-fire. Siumni's Watra is also the occassion for the dance performances, songs and picnic. The benefits from Watra help to pay for promotion of the Polish Highlander Culture - like a travel to Trailing of the Sheep Festival, etc. Marek Ogorek and Zdzislaw Miernicki are in charge of art and performance, Andrzej Tokarz is in charge of administration and promotions. Andrzej (Andrew) Tokarz is also a member of the Polish Highlanders Alliance board. He is also a president of PTDWA described below.
Polish Highlanders were also represented by Polish Tatra Working Dog Association (PTWDA). This organization is designed as a forum for Polish Tatra Sheepdog owners to share ideas and experiences. They brought beautiful Polish shepherd dogs. These are beautiful white and very intelligent dogs who serve not only to help to protect the sheep herds, but also as guard dogs and dogs that help to find lost tourists in the Tatra mountains.
Please, check the articles about Polish Folk Costumes in Different Regions of Poland - Past & Present , Polish Mountaineers - Folk Costumes, Tradition and History. See also the previous reports from the Trailing of the Sheep Festival (2006): Trailing of The Sheep Festival in Central Idaho with Polish Highlanders and Trailing of The Sheep Festival in Central Idaho - Basques and the Shepherds from Peru.
Below there are beautiful costumes of Polish highlanders górale from Trailing of the Sheep Festival, October 12-14, 2007 in Idaho - Hailey - Ketchum - Sun Valley.
I recommend Eyewitness Travel Guide to Poland (Eyewitness Travel Guides) by Teresa Czerniewics-Umer, Malgorzata Omilanowska, Jerzy S. Majewski, DK Travel Writers
This comprehensive book about Poland, showed below, may also be useful for you:
The Rough Guide to Poland by Mark Salter, Jonathan Bousfield