Beginning about 25 miles northeast of Greeley and extending 60 miles east, the 200,000-acre Pawnee National Grassland is a popular destination for hiking, mountain biking, birding, wildlife viewing, and horseback riding. Nomadic tribes lived in this desertlike area until the late 19th century, and farmers subsequently had little success in cultivating the grasslands. Although primarily grassland, the dramatic Pawnee Buttes, located in the eastern section, are a pair of sandstone formations that rise some 250 feet. A dirt road leads to an overlook that offers good views of the buttes, and from the overlook a 1.5-mile trail leads to the base of the west butte. The most popular springtime activity is bird-watching, when you're apt to see white-crowned sparrows, lark buntings, meadowlarks, thrushes, orioles, and burrowing owls among the 300-plus species known to frequent the area. Pronghorn, coyotes, mule deer, fox, badger, prairie dogs, and short-horned lizards are among the prolific wildlife.

There are many routes to the grassland; one is to follow U.S. 85 north 11 miles to Ault, then east on Colo. 14 toward Briggsdale, 23 miles away. As much of the grassland is interspersed with private land, those planning to explore the area are advised to stop at the U.S. Forest Service office, 660 O St., Greeley (tel. 970/346-5000).

In Greeley, the 20-mile Poudre River Trail is popular with in-line skaters, bikers, walkers, and runners. For more information, call tel. 970/336-4044 or visit the website.