If you are stuck in Tucson over spring break and need to get out of the house, grab a mountain bike and head for some of Tucson's more popular biking routes.

There are four major areas within biking distance from the University:

• The Santa Cruz River Park - For nice flat pavement and a great view of the emptiest, driest river wash on Tucson's west side, ride west on Speedway and pick up the trail, whic h runs perpendicular to Speedway, directly after riding under I-10. The roughly 3.5-mile trail route runs from Silverlake Road to Grant Road.

• The Rillito River Park - This paved trail runs east-west from Campbell Avenue to La Cholla Boulevard, rough ly a four-mile route. To get there, take Speedway Avenue west, turn right onto Campbell Avenue, and after riding 3.5 miles pick up the trail, which will be on your left.

• Starr Pass - For a rockier ride, bike five miles westward on East 6th Street unt il you pass Pima Community College. Signs will direct you to Starr Pass, which will be coming up on your left. Turn off 6th and ride uphill through the development, then turn left onto Starr Pass Boulevard. There will be a dirt road on your right, just b efore you reach the adobe homes. The ride is rough, but the route home is downhill.

• Gates Pass - If you want a good road ride, head west on Speedway Avenue until you reach Gates Pass Park. The majority of this eight-mile ride is uphill and on a wind ing two-lane road, so use caution. If you time the ride correctly, you can watch the sunset from the pass and still have time to bike back into Tucson before nightfall. Once again, the ride home is downhill.

  If you have access to a car, your biking choices double:

• Mount Lemmon - Biking down from the top is an enjoyable, easy ride. Arrange for a friend to drive you to Windy Point at the 14-mile mark, or further up to Summerhaven. The ride down can be col d at first, but the thrill of rushing down Mount Lemmon for over an hour and not pedaling is worth the initial chill. Be sure to wear sunglasses, because anything that gets in your eyes at 40 mph is going to hurt.

• Sabino Canyon offers paved biking before 9 a.m. and after 5 p.m. every day except Wednesdays and Saturdays. To get there, drive east on Speedway Avenue and turn left on Wilmot Road, which will turn into Tanque Verde Road. Turn left onto Sabino Canyon Road and follow the signs. The lower falls route is a two-mile ride, and the upper falls is a 3.8-mile ride. Admission is free.

• Chiva Falls - To get to the falls, take Tanque Verde Road until it turns into Reddington Road. Drive to mile marker #8, and parking will be on your right. Man y established trails are available and there is always the opportunity to find new routes.

• Catalina State Park also has numerous mountain biking trails. To get there, drive north on Oracle Road toward Oro Valley. Turn right onto Goulder Ranch Road an d continue driving eastward until Goulder turns into dirt. Park and explore.