Well I'll reply to your posting -- although considering it's two months old you may have already found your answers. Hemlock is a resident of moist, sunny-to-shady areas, often along rivers and streams. So they do like things somewhat moist -- especially by Nebraska standards.

They will do fine in full sun, although they will do fine in partial shade to almost full shade as well. Along with yews, they are the best conifers for shade.

They can get big -- like 150 ft tall in good time in good conditions -- but they'll do it slowly. Good luck.

-James