Write a letter to the Kansas DOT chief or office of counsel, explain the situation specifying the stretch of US/State hwy, not controlled access freeway, no signage indicating bicycles prohibited, and ask for clarification of the law. As you know Kansas has a lot of Mennonites, and where I live, they drive horse-drawn wagons at 4 mph on some U.S. highways. And I've seen 20-foot-wide combines doing 15 mph too.
Anyway, get the official confirmation of legality, and take or email a note to sheriff, with attachment, explain what happened, and ask that he inform deputies of cyclists' right to use U.S. highways, except freeways that have no-bicycle signs at onramps.
I didn't know that cyclists in Kansas can ride up to two abreast, which I think is very sensible.
(I'm from California where it's verbotten.
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I'm going to start riding this way with my spouse. She's skittish about street/road riding, now I can "shield" her by riding on her left.
It does conflict with the ride-as-far-right-as-practicable law, so I'd probably revert to single file on two-lane roads when cars approach from behind.
I ride right of the fog line if a 3+ feet-wide paved and debris-free shoulder is present, as a courtesy to drivers, but if it's 2-feet wide or less, I'm not going to risk my elbow getting clipped by somebody's mirror, and if it's got junk I'm not going to risk flats just to be nice, so I take the lane.