Sikkim is one of India's most affluent and more sparsely populated states, even though its population has increased 10-fold since it was annexed by India in 1975.

Gangtok, the fast-growing capital city, is stacked on the steep slopes of a 5,400-foot ridge. It's a friendly town and easy to walk around, although most of its new concrete buildings have little charm and exhaust-belching trucks and jeeps clog the main road.

When it's clear there are sweeping views of Kanchenjunga (also spelled Khangchendzonga), the world's third highest mountain.

There are several dozen hotels (the Tashi Delek and the Hotel Tibet are among the most popular and comfortable) to choose among, ranging from under $10 a night for a room in a budget hotel to about $60 (with meals).

Gangtok has a busy outdoor market; shops that sell Tibetan handicrafts and jewelry; an Institute of Tibetology; and an orchid sanctuary. Some of Sikkim's most interesting cultural sights are monasteries that can be visited on half-day or day trips from Gangtok.

The Rumtek monastery, about an hour's drive from Gangtok, is the seat of a Tibetan Buddhist order founded in the 11th century.

The main building has been recently rebuilt but in traditional Tibetan style with courtyards, prayer halls decorated with intricate murals, and monks' chambers. The maroon-robed monks, from schoolboys to men in their 80s, welcome visitors.

Another historic monastery is Pemayangste in western Sikkim. It sits alone on a forested ridge at about 6,500 feet, a lonely, contemplative place.

On one of its upper floors, reached by a candle-lit stairway, is a 12-foot high intricate carving of the heavens with hundreds of miniature wood figures - demons, birds, dragons and Buddhas. It was the life's labor of one of Pemayangste's monks.

Getting to Sikkim

Sikkim is in northeast India, tucked into the Himalayan range and its foothills. Americans traveling to India need a passport and visa; in addition, foreigners need a special permit to visit Sikkim (check with a tour operator or Indian consulate about getting a Sikkim permit). It's usually valid for 10 to 15 days. Additional permits are needed for trekking and can be obtained in Gangtok.

Sikkim does not have an airport. Most travelers fly from New Delhi to Bagdogra airport, near Siliguri in West Bengal.

Gangtok, the Sikkimese capital, is about a 4 1/2-hour drive up steep roads from there on buses (usually jammed), shared taxis (also jammed, often with 10 or more people in a jeep-style vehicle designed for 6) and tour-company jeeps or vans (the most comfortable way to go).

Trekking

Trekkers in Sikkim must go with a guide from a government-approved company; they cannot trek on their own.

Treks to Dzongri, and continuing beyond Dzongri for several more days to Goechala, can be arranged in advance through U.S. or British adventure-travel companies or in Gangtok through a half-dozen small tour companies there.

For those arranging a trek on the spot in Gangtok, the quality of guides, food and porters varies widely, so shop around (expect to pay $30-40 a day and up). Altitude sickness afflicts some trekkers to Dzongri so be sure a guide can accompany you down rapidly if needed. (Descent is the best cure for altitude sickness, which can be a very serious illness.)

A trek also can be part of a more extensive small-group tour of Sikkim and other areas of India, as was my trip with Trek Sikkim.

Such trips cost much more ($3,400 for a two-week Trek Sikkim trip, plus international air fare) but the quality of guides, hotels, food and transportation is high. A tour company will handle all arrangements, including Sikkim and trekking permits, and tours usually also include visits to New Delhi; the atmospheric hill town of Darjeeling in north India; Sikkimese monasteries and more.

These adventure-travel companies offer treks in Sikkim and other parts of the Himalayas:

-- Trek Sikkim: Nine reks this year to Dzongri/Dablakhang; other Sikkim treks by special arrangement. Phone its New York office: (212) 996-1758.

-- Cox and Kings: Upscale cultural tours of India by this two-century-old British travel company, plus a few Sikkim treks led by Hope Leezum Namgyal. Phone its New York office: (800) 999-1758.

-- The Seattle-based Northwest Mountain School is offering a Sikkim trek in the fall (organized with the Himalayan Mountaineering Institute, a respected group based in Darjeeling, India). Phone 634-3955.

-- Maleta's Star Class: Walking tours of Ladakh in the Indian Himalayas with an Austrian journalist/veteran India traveler (now based in Oregon). Phone (541) 344-8108. Or check the Internet at: http:/www.cyber-dyne.com/maletaus

The adventure-travel companies listed below, some of the biggest and most established in the business, offer treks and tours in the Himalayas. Many focus on Nepal and Bhutan, but there also are trips in India, Tibet and northern Pakistan.

-- Mountain Travel/Sobek: (800) 227-2384.

-- Geographic Expeditions: (800) 777-8183.

-- Wilderness Travel: (800) 368-2794.

-- Myths and Mountains: (800) 670-6984.

-- REI Adventures: (800) 622-2236.

-- Himalayan Travel: (800) 225-2380.

The "Speciality Travel Index" lists dozens more companies that offer small-group adventure tours in Asia. It's published twice yearly and is available in some bookstores or by phoning (800) 442-4922.

More information, books and slide show

-- For information on traveling in India, contact the Indian Government Tourism Office in Los Angeles, (213) 380-8855. Visa forms and information are available on the Indian consulate's Web site: http://www.indianconsulate-sf.org/

-- The Himalayan Explorers Club is a Colorado-based, non-profit club that provides members with information on Himalayan travel, runs a home-stay program in Nepal, and more. Phone (303) 494-9656 or check the Web page at: http://www.abwam.com/himexp/

-- A slide show and talk on Sikkim and Darjeeling is being held on Thursday at the Seattle Asian Art Museum at 7 p.m. It's by Tese Wintz Neighbor, an Asian history teacher and adventure-tour leader. It's free with museum admission. Phone 654-3182 for more information.

Among the most useful books for visitors to Sikkim are:

-- India: The Rough Guide (Rough Guides Publications). Contains a short but very good section on Sikkim, outlining its history, monasteries and other sights, accommodations and transportation.

-- Indian Himalaya (Lonely Planet). Similar to the Rough Guide, and with extensive information on Ladakh and other Himalayan areas of northwest India.

-- Fodor's: The Himalayan Countries (Fodor's Publications). Covers Bhutan, Nepal, northern India, northern Pakistan and Tibet. (Sketchy on trekking.)

-- So Close to Heaven: The Vanishing Buddhist Kingdoms of the Himalayas, (by Barbara Crossette, Vintage Books). Excellent history and perspective on Bhutan, Tibet, Sikkim and more.

-- Time Change, by Hope Cooke (Simon and Schuster): An autobiography of Hope Cooke, the American wife of the last king of Sikkim (and mother of Trek Sikkim tour leader Hope Leezum Namgyal).