Flat or nearly flat

Paved or smooth surface

Rolling, total climb up to 50 feet per mile (2500 feet in 50 miles)

Mostly groomed trail or dirt roads

Hilly, total climb between 50 and 150 feet per mile (2500-7500 feet in 50 miles)

Trail or dirt road with some rocks

Very hilly, total climb between 150-250 feet per mile (7500-12,500 in 50 miles)

Trail or dirt road with substantial rocks, roots and/or ruts

Mountainous, total climb more than 250 feet per mile

Very rough trail