Two thieves could face hundreds of thousands of dollars in fines and possibly years in jail after pulling off one of the highest-profile heists in Arizona history. Their loot: 17 saguaro cacti they uprooted two years ago from Saguaro National Park near Tucson. The 35- to 70-year-old plants each stand five to seven feet tall (saguaros grow to well over 40 feet, but young plants like these are easier to steal) and can fetch $2,000 apiece from landscapers. "We have an active patrol," says the park's chief ranger, Bob Love. "But we can't be every place all the time." To stop the pillaging, Love and his team will imbed radio-frequency identification tags, like those used to identify pets, in 1,000 cacti throughout the 91,000-acre park.