(MONEY Magazine) – Up ahead, steam hisses. A whistle blows. A uniformed conductor yells, ''All aboard!'' Your open-windowed railroad car jerks forward as you hear the , unmistakable chuff-chuff of a steam locomotive that is gathering speed. Puffs of smoke drift by. It's like something out of Back to the Future III, but it's now and it's real: you're riding the iron horse. Since the railroad preservation movement began in earnest back in the '60s, steam trains for tourists are operating all over the nation. The California Western Railroad out of Fort Bragg takes a spectacular seven-hour trip through redwood forests. From Atlanta, a restored 1926 locomotive of the New Georgia Railroad clickety-clacks along slowly to Stone Mountain, while the passengers enjoy a leisurely dinner. There are now at least 112 steam-train attractions. Costs range from $1.75 to $16 for a sightseeing ride, $30 to $40 for a dinner excursion. Museum fees are $2 to $5. Last year, this steam-powered industry generated about $18 million in revenues from more than 2.4 million patrons. This year, that number is expected to reach almost 3 million. The 1990 Steam Passenger Service Directory, a handsome guide to railroads and events, costs $8 from Locomotive & Railway Preservation (P.O. Box 599, Richmond, Vt. 05477; 800-356-0246). Here's a sampler:

-- The Mid-Continent Railway, North Freedom, Wis.: This authentic re-creation of a steam-powered branch line boasts 1900-era equipment.

-- The Cumbres & Toltec Scenic Railroad: Ride an observation car on a 64-mile line from Chama, N.M. to Antonito, Colo. by way of 10,022-foot Cumbres Pass, Toltec Gorge, some high bridges and two tunnels (see the map above). -- Chattanooga choo-choo: Take a 45-minute, six-mile Tennessee Valley Railroad Museum round trip touching Civil War history as the train crosses Chickamauga Creek and passes through the 986-foot-long Missionary Ridge Tunnel. -- The Puget Sound & Snoqualmie Valley Railroad, between North Bend and Snoqualmie, Wash.: This line has fall foliage runs plus special Halloween and Santa trains.