wildherb

This is probably the third best intermediate run in California, after the Stanislaus Camp 9 run (under New Melones Reservoir most of the time) and the South Fork of the American near Coloma. The Trinity is seldom or never crowded, and runs all year long, although it could be too high after big rainstorms. Water is clear and clean, and somewhat warmer than Sierra rivers. Camping is plentiful, although possibly mosquito-infested in springtime. Motel rooms are often available if you prefer not to rough it. Best of all, there are no put-in or take-out fees!

Two drawbacks are the long drive from population centers, and the short river distance. The second problem can be overcome by aggressive surfing, by making two runs in a day, or by combining this run with class II stretches downstream. David Elliott made these remarks about downstream runs:

Big Flat to French Bar, 8.3 miles. While it may look flat from the road, this section offers quite a few nice class II-II+ rapids. This is a good section to tack onto the end of the Pigeon Point run on a hot day when the river is more inviting than the campground. There are plenty of swimming spots between the rapids. French Bar is a good take-out for the last day of boating, because the rocks make a good place to dry out boats and clothing for the trip home. When flows are high, this can be a good starting point for a run all the way to Cedar Flat, but don't even consider the full run below 1600 cfs, and even then you'll want to get on the river by 11:00 AM.
French Bar to Hayden Flat, 3.4 miles. The California Whitewater book mentions a class II+ rapid and a cave right below French Bar, but I have never seen the cave and the rapid doesn't compensate for the run below. This is the boring section. If you aren't doing the entire run to spend the whole day on the river, this section really isn't worth it.

Hayden Flat to Cedar Flat, 6.7 miles. This section has the best rapids of the three, and is more popular with kayakers and tubers than the sections above. There are several class II+ rapids with big holes and waves, and one long gorge that ends in a big hole (see photos of the Trinity above Cedar Flat). The gorge borders on class III and can be seen from the road. Just above take-out, Don Juan rapid contains some big waves.

For class II people at flows below 2000 cfs, choose either Big Flat to French Bar, or Hayden Flat to Cedar Flat; at flows above 2000 cfs, the whole run is recommended. For class III people, run Pigeon Point to Big Flat every day you can. Add on the section to French's Bar if flows are higher than 2500 cfs or if you just want to relax (below 1000 cfs however, don't bother with the class II sections).

This mile-by-mile description covers only the class III section from the north fork confluence (above Pigeon Point campground) to Big Flat (near a private and the USFS campground).
mile
0
Put in under the highway 299 bridge over the North Fork. Upstream the scenery has been degraded by hydraulic mining.
.2
Pigeon Point USFS campground on the right bank makes an alternate put-in, but involves a carry down to the river.
.5
unnamed class II+
Just beyond a cliff on the right, the river drops along the left bank and piles straight into a rock at the bottom.
2.1
slalom, class II+
Close to the highway, a long rock garden offers many opportunities for ferrying and surfing.
2.4
Z Drop, class III
The river narrows and drops almost a meter thru a rock slot. At low and moderate flows you can scout from bedrock on the left. At high flows the bedrock creates a large reversal.