Rainmaking might conjure up images of traveling sideshows, snake oil salesmen and rituals where people beat on drums.
But out West, there are those who say they can make rain and snow - and there are those who believe them.
Unproven by science and unheard of in the East, the practice of making rain by seeding clouds with chemicals is attracting more support from western municipalities, states, utilities and ski resorts.
Denver Water officials agreed to spend $699,000 this winter on cloud seeding - and had no trouble persuading 10 municipalities to pay $200,000 of that cost.
Chips Barry, chief operating officer of Denver Water, says any criticism about the seeding was probably doused by the severity of the region's drought.
"We're having what was officially declared as the single worst drought year on record," Barry says. "There didn't appear to be any serious opposition to this at all. Things are so dry here."
But some experts say that seeding is still unproven and little better than taking your money to a casino - you could win big, but you're more likely wasting it.
"There is no hard science to support that it works," says Hugh Willoughby, a research professor at Florida International University and a former meteorologist with the National Oceanic and Atmospheric Administration. "I certainly wouldn't advise anyone to get into a big cloud-seeding program."
Willoughby says a 20-year study by NOAA on cloud seeding of hurricanes ended inconclusively in 1983. There were too many variables in the weather to scientifically evaluate the effects, he says.
"I've never seen a study with results that someone was able to duplicate and show the same results," he says. "I'd like to see one."
The U.S. Department of the Interior's Bureau of Reclamation is looking for verifiable results as well, with $2 million in grants to be given to Western utilities and states for basic studies on cloud seeding.
Despite the absence of proof that seeding works, some scientists say that with droughts and population growth parching many parts of the country, it might be time for a closer look at "weather modification," as supporters prefer to call it.
"I think water resources is going to be a huge issue in this country, and weather modification is going to be a major part of that conversation," says Joseph H. Golden, a senior meteorologist with NOAA in Boulder, Colo.
Golden says, however, that there is insufficient information about whether seeding would work in the East, and that makes seeding an unlikely solution to droughts in this part of the country.
Maryland, along with the rest of the Eastern United States, has different weather patterns than the West, where cloud seeding is common, he says.
Advocates say all that is needed to convince skeptics is a comprehensive study of cloud seeding.
Lawrence M. Hjermstad, a meteorologist whose firm is seeding the skies near Denver, says he is trying to find funds and researchers for a study to verify that seeding works. He says the understanding of how seeding works - which clouds to seed and how heavily - has come a long way since most of the studies were completed in the 1980s.
"I've been trying to find some scientists to put some study together, but I can't find anybody who has the funding to put one of these studies together," says Hjermstad, founder of Durango-based Western Weather Consultants.
Advocates say cloud seeding is supported by basic chemistry and goes back to experiments conducted in the 1940s.
Clouds that contain moisture are usually seeded with silver iodide to increase precipitation or prevent hail damage. The chemicals are either released from an airplane or sprayed by a land-based generator about the size of a household furnace.
With both airborne and land-based generators, silver iodide is heated until it vaporizes and forms microscopic crystals. The crystals enter the clouds and collect moisture from them the same way a glass of ice water will attract beads of water. The moisture that collects quickly grows large enough to fall as rain or snow.
To make it rain, generators fueled by propane are placed at an altitude of at least 7,500 feet on a cloud-hugging mountain.
To reduce hail damage, planes fly into forming storm clouds and seed them, sapping moisture and depriving the cloud of the moisture needed to form large hailstones.
Seeding has inspired its share of testimonials.
"I know that it works," says Bill Jensen, chief operating officer at Vail Resorts Inc. in Vail, Colo.
Jensen says seeding has increased snowfall 15 percent to 18 percent in Vail during the past 27 years and helps ensure the 200 inches of snow needed for a successful ski season. The company will spend at least $150,000 this year to seed clouds over 5,300 acres of ski trails, he says.
North Dakota officials also are convinced that seeding reduces hail damage to crops.
Darin Langerud, a meteorologist and the director of the North Dakota Atmospheric Resources Board, says the state has seeded since 1951 and plans to spend $600,000 this year to seed for rain and reduce hail damage.
He says an analysis of 50 years of insurance claims shows a 45 percent reduction in crop hail losses in the six counties that seeded, compared with 12 other nearby counties subject to the same weather conditions that did not seed.
Todd Adams, a spokesman for the Utah Division of Water Resources, one of 10 states that issue permits to seeding firms, says that a comparison of seeded areas with nonseeded areas shows seeding has increased snowfall 10 to 20 percent.
He says the state has regulated seeding since the 1970s and will split the costs this winter with local utilities to try to increase the snowpack by paying $285,600 to a firm that will operate 100 seeding generators in five mountainous areas.
But Willoughby and other scientists remain skeptical about the benefits of seeding.
Willoughby says reports showing a percentage of increased precipitation fail to account for long-term weather patterns and seasonal fluctuations of snow or rain.
Ski resorts might advertise cloud seeding to drum up business, he says, and utilities might face political pressure to seed, particularly if they impose water restrictions. But there's no conclusive proof that it works.
"It might not hurt to advertise that you've got cloud seeding going on, so that you might have more snow than the lodge down the road. From that standpoint it does make economic sense," he says.
Denver Water's decision to seed was inspired by a three-year drought that had reservoirs in nearby Summit County down to 48 percent of capacity this fall - about half the usual supply for that time of year.
The utility imposed a series of restrictions on outdoor water use this summer and banned watering lawns Oct. 1.
It is the first time Denver has seeded in 25 years. But Barry, the city's utility official, says he wrote to 21 neighboring jurisdictions asking for help in paying for the seeding, and half of them chipped in.
Snow has fallen three times since seeding began Nov. 1. But Barry acknowledges that he is unsure whether the seeding added to the snowpack.
"I'm absolutely certain that it would've snowed anyway," Barry says. "The question is, did we make it snow more? It's impossible to say for sure."