Approximate - nearest available gauge. Use as general reference only.
This is not on Devils River, but is a 'carry-up' from the confluence of Devils River and the Neshota River (whereupon both cease to exist, and they become the West Twin -- one of two rivers that flow into the city of Two Rivers, WI). Looking just upstream of the confluence, on the Neshota River, you will see a fine set of ledge/waves. Many boaters will find it worthwhile to carry up to run this fine sequence.
The near shore (river-left of the Devils River, river-right of Neshota River) is privately owned, with a cabin/house present. While the other shore is also privately owned, it is wooded with no home and yard, thus we advise ferrying across to river-left (of the Neshota/West Twin), to carry up on that shore. This also shortens the carry a bit, since you will be carrying up the inside of a bend in the Neshota River. Be careful walking through this wooded area, as there are numerous locations with old barbed wire down on the ground. I generally recommend carrying a good ways upstream, above the bend in the river, to put in and enjoy this fine ledge sequence.
The sequence starts with a single short (~1') ledge which spans the river, and can provide some minor play when flows are adequate. It could be worth carrying up to this point just to check out, and to warm-up the play muscles before dropping into Devils Meet Ledges. The meatier action will be Devils Meet Ledges, where most repeat play is likely to be done by shorter carry-up.