Really good chance the higher elevations will still be covered in snow....if we get more snow LOL. I've just ridden a short section in the Ochocos east of Prineville and I know it would be too much snow in April for that area. Malheur Ford might be too deep as well.
If I was wanting to ride in late April, I'd head for the Alvord/Fields area. It's the desert!! Probably set up camp at Willow Hot Springs for a couple nights and day ride from there.
Let me know if you want some route ideas.