(Tricityherald) - Tractors still dot the fruit-and-nut themed roads (plum, pecan, apricot) of Canyon County's Sunny Slope, but these days party-themed limousines and weekend wine tourists are also in evidence. Their quarry is a cluster of mostly small wineries with an increasingly big reputation. "We have eight wineries within 10 miles, which is enough for a two-day trip," said Ron Bitner, who recently opened a small bed-and-breakfast at his hilltop winery overlooking the Snake River south of Caldwell. Expand your search across Ada County and into Washington and Owyhee counties, and the Treasure Valley boasts more than half of the state's 43 wineries, a tally that has nearly quadrupled since 2002, when Idaho had 11 wineries. That's a fraction of the explosive growth seen earlier in Oregon and, especially, Washington. They rank third and second among all states in number of wineries, eclipsed only by behemoth California. Idaho comes in at No. 22, tied with New Mexico, in Wine Business Monthly's most recent ranking.