Molly J. Smith

There's one more reason to indulge in Girl Scout Cookies this year: In 2012, the Girl Scouts of the USA celebrates its 100th birthday. Juliette Gordon Low formed the Girl Guides in 1912, modeling the organization on England's Girl Guides and Boy Scouts. Low changed the name to Girl Scouts in 1914, after she was informed that scouts were sent out first and guides second — she believed her girls would be "second to none."

Arizona's first troop was formed in Prescott in 1916, though a troop in Ajo was the first to be officially chartered, in 1918. Today, there are more than 40,000 Girl Scouts and 14,000 adult volunteers in the state, and councils in Phoenix and Tucson.

The Southern Arizona Council spans eight counties and owns the only Americans With Disabilities Act compliant cabin in the area. Located in the Santa Catalina Mountains, it was donated to the Scouts by the Angel Charity for Children.

The Phoenix-based Cactus-Pine Council has its own Girl Scout Historical Society to document the organization's rich history. Six volunteers, all of whom are lifelong members of the Scouts, are responsible for organizing and cataloging everything from Girl Scout handbooks that date to the 1930s to all the uniforms worn in the past century. They've collected more than 500 original uniforms, including two replicas of the first uniform worn by Gordon Low in the early 20th century.

The society will display some of its artifacts in museums around the state — in Apache Junction, Tempe and Wickenburg, as well as the Girl Scout Museum in Phoenix — as part of the 100th anniversary celebration.

And though the organization has evolved over the past 100 years, its fundamentals haven't changed much.

"There's an old saying that's just as honest today as it was back then, and it's that we encourage girls to be thermostats and not thermometers," says Historical Society volunteer Joyce Maienshein. At 85, she's been with the Girl Scouts for 66 years. "Thermostats set the temperature, and thermometers just record it."