On each of our treks, we spent 25 days on the trail, with another four or five in Katmandu. Many outfitters shorten trips to Everest, the most popular trekking region, by as much as a week (and several hundred dollars). They fly customers to a grass airstrip at Lukla, a small village more than a week's trek from the Everest base camp. (Since nothing goes to waste in Nepal, the airstrip serves as yak pasture when planes are not landing.)

Try to avoid starting your trek by flying to Lukla. Fog in the Katmandu Valley or clouds at Lukla can delay the start several days. And leaving from Lukla also increases the tendency toward altitude problems (don't go too high too fast!).

A number of adventure travel companies offer treks in Nepal; the following is a sampling of those available this fall. In most cases, each of the companies listed offers a broad range of treks in the Everest and Annapurna areas, as well as other regions of Nepal. Most treks require a good-health certificate from your doctor, who should be able to recommend any needed immunizations. (Recently the State Department, referring to a significant increase in cases of Type A meningitis, advised visitors to Nepal to receive meningococcal meningitis vaccine. The disease has been particularly noted outside the Katmandu Valley.)

Prices are per person and include all living expenses on the trail, as well as accommodations in Katmandu, but do not include international air fare to or from Katmandu. Dates given are when the group leaves the United States; the actual trek begins about five days later.

WHAT TO TAKE: Upon receipt of a trip application, your trek outfitter will send you a list of the gear you should bring -- a sleeping bag, a down jacket, water bottles and so forth. Some trekking companies rent sleeping bags; and Katmandu has an active market in used expedition gear for anyone needing last-minute items.

GETTING THERE: You can reach Katmandu via either New Delhi or Bangkok. Trans World Airlines lists a round-trip fare from Washington, via Delhi, of $1,325; the fare from Seattle to Katmandu on Thai Airlines, via Bangkok, is $1,452. Both fares carry restrictions, including limited stopover privileges.

Much of the traffic into Katmandu is on Royal Nepal Airlines, which seems prone -- particularly in the Delhi Airport -- to lose track of reservations. It can prove most disconcerting to arrive in Delhi in the middle of the night (the time most international flights arrive) to find you lack a reservation onward to Katmandu. A waving of my ticket, together with a firm declaration of my intent to board the airplane, worked for me.

A final caution: If you must take your vacation in the summer, skip Nepal; trek instead in India's Kashmir or Alaska. Nepal's summer monsoon shrouds the peakd you came to see; the time to go is from mid-October until the snows arrive to block the high trails in early December.