Pinus ponderosa
- Description, images, and range maps, including several proposed subspecies.
- http://www.conifers.org/pi/pin/ponderosa.htm

Pinus ponderosa (Ponderosa Pine)
- Brief fact sheet with photos of tree, bark, fruit, flower, and leaf.
- http://www.cnr.vt.edu/dendro/dendrology/syllabus/pponderosa.htm

Pinus ponderosa (Ponderosa or Yellow Pine)
- Photos and facts on the physical features of this tree and its leaves, cones, and bark. Habitat information included.
- http://www.for.gov.bc.ca/hfd/library/documents/treebook/ponderosapine.htm

Pinus ponderosa var. ponderosa
- Information on distribution and occurrence, value and use, characteristics, and fire ecology.
- http://www.fs.fed.us/database/feis/plants/tree/pinponp/

Pinus ponderosa var. scopulorum
- Information on distribution and occurrence, value and use, characteristics, and fire ecology.
- http://www.fs.fed.us/database/feis/plants/tree/pinpons/