I put off a post about the southwestern white pine, Pinus strobiformis, until after Christmas because I figured it wouldn’t be of much use as a holiday tree. To my surprise, a site from Kansas identified it as such. The Covered Bridge Ranch in Montrose, Colorado also included it on a chart of its trees for sale for holiday decoration.

This variety of conifer has five needles growing per fascicle and each leaf may grow up to four inches in length.
Pinus strobiformis is found in the southwestern states of Texas, New Mexico, Arizona, and the southwest/south central counties of Colorado (Ackerman, Jennifer, Flora of Colorado) where it may grow up to 9000 feet in elevation. Like many other trees it has other common names such as pino enamo, border pine, and Mexican pine (North American Trees, Preston and Braham, 5th edition.)

According to the US Forest Service, although used for window frames and some cabinetry, this species is not valuable as lumber due to its tendency toward crooked growth. It is sometimes grown for its ornamental value, and some dwarf versions are available.

The Lady Bird Johnson Wildflower Center lists this species as having large seeds, which have served as food for both wildlife and southwestern tribes. At least one paper reports the seeds are a food for black bears. Practical Plants likens the seeds to piñon nuts with a harder shell. This website also mentions a vanilla flavoring agent from the resin. Like most other pines, the resins and other parts of the plant have been used as disinfectants and medicinally for many conditions.
The Gymnosperm Database lists the largest tree in the US as being in the Lincoln National Forest of New Mexico. This tree has a circumference of nearly five feet, is a bit over 111 feet tall, and has a crown spread of 62 feet. The oldest tree is also in New Mexico but is part of the San Mateo mountains. In 2006 it was said to be 599 years old. The tallest specimen, though, is in the San Juan Forest of Colorado. In 2014 it was measured as being nearly 128 feet tall.
To find C173 Southwestern White Pine (Pinus strobiformis) in Fort Collins City Park, start near the corner of Mulberry Street and Sheldon Drive. This specimen is on the east side of the road, behind a larger conifer, more or less across from the outhouse on the W side of the road.

Note on pinecones. It seems like conifer cones would be a useful way to help identify what kind of tree you are looking at. I found this specimen under the pine tree, but does it actually belong to this tree? It was the only cone. Between this tree and the conifer nearer to the road were strewn a number of other, slightly different cones. Descriptions of the white pine cone vary. How and where the cone grows on the tree can be of use in identification. Alas, no cones were visible on this tree at the time of viewing, eliminating the direction of growth as a helpful indicator.