Sleigh rides across snow-covered horse pastures. Cross-country skiing or snowmobiling along alpine trails. Spotting deer, elk and moose at their winter feeding grounds. Toasting marshmallows over a blazing fire in a cozy log cabin.

If your image of a family vacation at a guest ranch has room only for horseback riding, swimming and fly-fishing in rushing streams, think again.More and more Western guest ranches are staying open for the winter and (equally wintry) spring these days, and welcoming families as well.

Ranches offer a nice alternative to ski resorts for families who want to have a winter vacation that takes advantage of the weather, rather than escape it. There are no lift lines to stand in, no expensive equipment to buy, no lift tickets to purchase.

During the winter vacation season, the focus of ranch activities is still on the outdoors, with opportunities for plenty of vigorous activity. But ranches in the winter also seem made for carefree relaxation - for hours spent cuddled up in a hand-hewn lodgepole pine bed with your 5-year-old and a good book, for daily soaks in a hot tub surrounded by mounds of snow, for nightly star-gazing under a brilliant Milky Way.

The 1991 directory of the Colorado Dude & Guest Ranch Association lists 16 member ranches that are open in the winter months.

During this period, rates are likely to be lower than in the summer. That's partly because there may be fewer organized activity programs, particularly supervised children's programs. But it's almost always possible to arrange some spot baby-sitting so that parents can get out on the cross-country ski trails without kids in tow.

Among those Colorado ranches that welcome guests in the winter and offer children's rates:

- Aspen Lodge Ranch Resort. This is nowhere near the Aspen of ski and jet-set fame. Rather, it's just outside Estes Park, the home of Rocky Mountain National Park (it's named for Colorado's graceful state tree).

Towering Long's Peak (14,000 feet) provides the backdrop. Although it began life as a fur trapper's cabin, Aspen Lodge is now a sprawling resort with modern amenities and a ranch flavor. Because of its size (there's room for 150 guests), it can offer many more opportunities for winter activities than small ranches can. Downhill skiing and instruction are available at nearby Ski Estes Parks. Call 800-332-MTNS.

- C Lazy U Ranch. The concept of "roughing it" takes on new meaning at what may be the only Mobil five-star, AAA five-diamond ranch in the country. Guests at this ranch near Granby have the use of 13 miles of groomed, cross-country ski trails and acres of virgin powder; equipment, lessons and a guide service are included in the daily rate. The Winter Park/Mary Jane downhill ski complex is 25 miles away by complimentary shuttle.

Two Belgian draft horses, Levi and Strauss, are available to pull a sleigh through the countryside, and there's ice skating on a pond and sledding down a half-mile driveway and special tubing hill. And perhaps the best news for parents is that a supervised children's program takes charge of kids 3-12 years old every day. Call 303-887-3344.

- The Colorado Ranch Resort. Another ranch-flavored resort, this one sits near Granby in the heart of the Arapaho National Forest. Here there's an indoor pool and hot tub and a bowling alley. Call 800-332-2656.

Coulter Lake Guest Ranch has been operating for more than 50 years, so owners Norm and Sue Benzinger must be doing something right. It's situated 21 miles northeast of the town of Rifle (an Interstate 70 exit) in the White River National Forest. Snowmobiling and cross-country skiing are popular here in the winter months. The atmosphere is intimate and cozy (the ranch has room for only 30 guests in eight cabins). Call 303-625-1473.

- Diamond J Guest Ranch, near Meredith in the White River National Forest, offers a real lure to families: housekeeping cabins. It's not too far from Aspen, either, so families who like to ski can get in some time on the slopes. It also offers easy access to the Tenth Mountain Trail route, a hut system for back-country touring on skis. Call 303-927-3222.

- Focus Ranch, in the high mesa country on the Colorado-Wyoming border, is a working cattle ranch that also accepts guests. Here you can get an intimate glimpse at life on the range, and even help with the chores. Call 303-583-2410.

- Home Ranch Resort is for families who crave comfort. It's a member of the exclusive Relais & Chateaux hotel group and has a Mobil four-star rating (with corresponding prices). It's close enough to Steamboat Springs to permit downhill skiing and easy access to night life (there's a free shuttle to get you there). Ice fishing is one of the more unusual winter activities, and there's a special recreation building for kids. Call 303-879-9044.

- Peaceful Valley Lodge and Ranch Resort, near Lyons, successfully melds European hospitality and architecture with Western scenery and activities. Co-owner Karl Boehm is a former professional skier and Austrian refugee, and he set out to create an Alpine lodge in the Rockies. Snow coach tours are one of the winter activity highlights that even the sedentary can appreciate; a solar-heated, indoor pool of Olympic proportions can make you forget that it's winter outside. Call 800-95LODGE.

- Sylvan Dale Ranch, near Loveland, has been run by the Jessup family for 40 years. It has two rate structures - bed-and-breakfast only (extremely reasonable), or American Plan. Besides spectacular scenery, it offers all the demanding activities of a working ranch. The Big Thompson River runs through the property. Call 303-667-3915.

- Vista Verde Guest and Ski Touring Ranch is nestled in a scenic valley (elevation 7,800 feet) and surrounded by the 13,000-foot peaks of the Zirkel Wilderness area. It has an indoor whirlpool and sauna to soothe skiing-strained muscles. The log cabins are exceptionally cozy with their calico curtains, hand-sewn quilts and old photographs. The Steamboat Springs ski area is nearby. Call 800-526-RIDE.

- Waunita Hot Springs Ranch. The 175-degree bath water here comes from the ranch's own mineral hot springs, which also feed a gigantic outdoor pool in the summer. The ranch, near Gunnison, has been run by the Pringle family for 28 years on the western side of the Continental Divide. There's an old-fashioned game room that's popular with kids. No alcohol is permitted on the premises. Call 303-641-1266.

For a free copy of the annual directory of the Colorado Dude & Guest Ranch Association, call 800-441-6060. But be sure to contact each ranch individually for detailed information about their facilities and rates.

It's not a member of the Colorado Dude & Guest Ranch Association, but Snow Mountain Ranch, in Winter Park, is a wonderful winter destination for families - at not-for-profit prices!

The ranch is operated by the YMCA of the Rockies, along with the more widely known Estes Park Center. It's enormous, by ranch standards, with accommodations for 1,200 guests.

The Winter Park and Silver Creek downhill ski areas are nearby, and cross-country skiing, ice skating and sleigh riding are available on the premises. Call 303-887-2152.