Trails

How to choose a trail

1. Start with the class. Class 1 is hiking; Class 2 asks for hands now and then; Class 3 is moderate scrambling. The class is not on the card, so read the map: an easy trail walked with simple walking is Class 1; steeper off-trail scrambling where hands are used for balance is Class 2; and even a Class 1 day keeps its risks of weather, water crossings, navigation and altitude (TM-01, TM-03).
2. Length is on the card; gain is not yet. A trail that climbs a canyon wall is a different day from one along a creek of the same length, so open the map and read the contour lines before you commit, and plan the descent as load: running a 9-degree downhill, impact force peaks ran about half again higher than running on the level (TM-08).
3. Be down by noon. Mountain thunderstorms build in the early afternoon; after the last rumble wait 30 minutes before moving on, and the car at the trailhead is the safe place, a tent or a picnic shelter is not (TM-27, TM-28).
4. Carry food and water by the hour: about 25 to 75 g of carbohydrate an hour in small portions at rests, 6 to 12 oz of water every 15 to 20 minutes, pale yellow urine as the check (TM-13, TM-14).
5. A trailhead above 8,000 ft is altitude from the first step. Mountain sickness shows as low as 5,000 ft, and above 8,000 ft the day's base should rise no more than 1,000 to 2,000 ft a day (TM-22, TM-24).
6. Dogs, bikes and seasonal closures are set by the land manager, not the map. The Boulder open space pages say which trails allow dogs off leash with the voice-and-sight tag, which are on leash, and which are closed to dogs. Uphill has the right of way where that custom holds, the slowest walker sets the pace, and the seven Leave No Trace principles are the trail's manners (TM-34, TM-35).
7. Out-and-back doubles the figure on the card; a loop is the figure once. The map shows which it is.