Colorado Yurt Company in montrose, colorado makes excellent tipis. I dont have any business affiliation with them.
I can personally vouch for the quality of their products, I used to own a 16' tipi that I lived in while I built my cabin.
We used to make Native american tipis do not any more.
I would be happy to share the basic pattern or I guess if others really wanted help a group make one..
Here is my favorite company to recommend because I know their work and helped them with their very first tipi..They are also out of Polson Montana and native american.
Justin Rhodes 45 minute video tour of wheaton labs basecamp