Limber Pine (Pinus flexilis): Long-lived and slow to grow; a medium sized conifer used for rough construction, railroad ties, and poles. It grows from Alberta and British Columbia south to New Mexico with notable populations found in the Dakotas and Nebraska. It grows where precipitation is minimal at best, the humidity is low, and the temperature ranges are wide. It is very cold hardy (< - 43 o F), quite windfirm with a strong fibrous root system, and relatively intolerant of shade. Because it does withstand severe wind and dry conditions this pine would make a good shelterbelt tree but it is slow growing which may discourage its use for shelterbelts. Its hardy nature has allowed some limber pine to grow to be well over 1,000 years old. One of these pines in Idaho was aged to be 1,650 years old (USDA, NRCS Plants Database).