I've found some natural/undyed wool being sold straight from the farm for a much more affordable price than other yarns I was looking at. I've never worked with this type of wool

New England's Narrow Road – Knitting projects, patterns and reviews

Prime Time Knitter

I'll give you a topic

Natural Brown Sheep worsted weight 3 ply undyed soft farm raised

Knitted up Jason's Cashmere hat with Malabrigo rios yarn for my

Dyeing Wool with Natural Plant Dyes - Timber Creek Farm

I've found some natural/undyed wool being sold straight from the

Blog — Tanis Fiber Arts

How to Wash and Dye Wool Chickens in the Road Classic