I booked a "From Tree to Table" tour through the Olivo Website. We wandered around the olive grove and was able to get really close to all the trees. Helen talked to us about their products and walked us through all the varieties of olives they grow.
The property is beautiful, and we were able to taste their full range of products. Was fun to learn how to taste them properly :-)
It is really close to Martinborough and the owners are extremely friendly and helpful. We walked away with a bottle of their Porcini infused oil which we have used a few times in the last 2 days now! Definitely an excellent way to spend a few hours between wine tasting at the nearby wineries.
Probably not walking distance, but grab some bikes and you'll be fine!