USGS Gage Station CFS at Dayton.
The access point for the upper run is about five miles north of Dayton on county road #90 in Tongue River Canyon. There is a one mile Class IV/V piece that can be reached by hiking up a trail from the campground at the end of the road. Depending on the runoff, the half-mile run from the end of the road to the first bridge is either a solid Class III or Class IV. The next mile section, past another small bridge to below a small drop, is Class III. The final four mile stretch to the landing in Dayton is a fast Class II with at least one fence. Float time from the end of the road is about one hour. All scouting can be done from the road or as you pack upstream.
The best put-in for the lower section is at a small campground near the bridge in Dayton. The parking fee I paid was one dollar per day. This part of the river is fairly fast and contains numerous tight bends. There are many fences (some of which are electric), logjams, sections of carbody riprap, overhanging branches, and the possibility of fallen trees spanning the entire river is great (three when I floated it last). As a result, the beginner will have some problems navigating this section.
About thirty minutes downstream is a small diversion dam. At high water it poses no problem, but during low flows you'll have to drag around it. An hour further to the northeast is a county bridge. From here the river begins to slow down a bit and there are deep pools of quite water between the bends. Three hours from Dayton, Wolf Creek comes in from the south and you pass below another county bridge on the outskirts of Ranchester. You then float through town for a bit to a diversion dam and landing at a small park.
Below the diversion dam in Ranchester the river meanders along to the east. The water is slow and lazy for the most part and aside from a few fences, it's an easy pace for the beginner. The river follows along the highway and railroad and after about two hours you come to a county bridge. About two hours downstream are the US-14 and I-90 bridges near Monarch and Kleenburn. A half-mile further is a possible access point off US-14. (A dirt road goes down to the river and is obviously used for access but I do not know the legal status.)
Below are several mine site bridges and a diversion dam at Acme. At high flows you may be able to float over it but I had to line it. Just downstream from Acme is where Goose Creek comes in from the south. From the Goose Creek Confluence, the river makes a series of large loops and begins heading northeast. This is a particularly beautiful area here as the river travels past hills of red scoria rock, cedar trees, and ponderosa pines. The river swings close to W-338 several times and two hours from Acme is a diversion dam that you can either line or drag around. Just below this dam is the W-338 Bridge. There used to be a small access road here, but the area was under road construction so I don't know what it will be like in the future.
Photo Caption (image not shown): The Tongue below Dayton can have numerous downed trees blocking the entire river. Also, some of the fences are electric!