Joel Mill:
There probably are several different types of wood available in your area.
What you use depends on what you want to see as a completed project. If you want Doug fir then get that.
There are many ways to find timber sources for your area. One is clicking on the resource guide on the home page of the TFG and follow the links to the search page. Then select "Lumber" in the keyword box. Select your state in the state box, and select "Timber Products" in the Category Type box. This will supply you with a list of companies mostly in your area that can provide you with lumber and/or timbers.
There are other ways and websites that can help you find timbers and types of wood available in your area. If you don't find enough with this list then post again and I'll help you find more.
Leaving your timbers natural depends on the type you do finally select. Some types of wood are naturally rot resistant, others are not as much. Just remember, probably as you know, light colored woods darken with age and dark colored woods lighten with age.
Also, there are clear wood preservatives you can put on you timbers to help them to last and not greatly change the color of the natural wood.
Recently there was a post here about TWP a product that is a Total Wood Preservative. I have not used this produce, yet, but it seems very interesting, and could be just the thing to help timber framers and their frames.
Good luck with your project, and keep asking questions.
Jim Rogers
