Ponderosa Pine...
Very similar in appearance to Ponderosa Pin vigas in regard to color and knot structure.  When used in a natural application (no paint or stain) they blend well together.  The product is cut green, and generally installed green, so care needs to be taken to avoid twisting and blueing, etc...

Douglas Fir...
The product is structurally stronger and less likely to twist than Ponderosa Pine, but has more tendency to check and split while seasoning.  Douglas Fir has contrasting color when used with Ponderosa Pine.

Southern Yellow Pine...
This product is structurally similar to Douglas Fir, with an appearance similar to Ponderosa Pine.  These timbers are also kiln dried, which eliminates most concerns for shrinkage and warpage.