Hello Debi, 

Thank you for reaching out and for the photo.  The black spots are likely old wounds, Our Douglas County Horticulture Specialist says he would not be concerned about those and that the cracks do not look to be biotic in origin. 

It could be damage from water-induced swelling, from transition to mature bark (seems small for that, though), or twisting/torsion from high winds?

Hope that is helpful. 

Have a good day!