I returned from a fishing-camping trip this weekend and took a new road back home and passed a lake that doesn't show on any map that I can find. I'm hoping someone might know about this lake and what kind of fish are in it. The lake is about 200 acs in size and along the north side of the Pinto Ridge Rd about 5 miles north of Billy Clapp Lk. and south of Coulee City. The large canal that comes out of Banks Lk is right beside the lake. The lake looks fairly new or maybe the canal sprung a leak and formed the lake. The Topo map I looked at shows a Trail Lake and Trail Lake Coulee where the lake is. Trail Lk is listed as only 6 acs and this lake is much larger. There's a road that runs along the lake and canal for several miles. Several roads go into the water and there has been some recent dozer work done to clear a road and boat launch area. I saw some fishing garbage, so was curious as it looked like a lake worth trying at a future date. Anyone know anything?

Do you know what national forest that area is in? Forest Service maps are pretty good at listing lakes, even small private ones

You have likely discovered Trail Lake itself or one of the other shallow seepage ponds that form near the Canal out of Banks.
Trail lake is poor fishing for mainly occasional escapement of trout and spiney rays from Banks itslef.
Any of the other ponds in that area are shallow and incapable of holding trout over winter.
If you hoped you'd discovered a new great fishing spot.......forget it.

This wasn't a small pond it was big!. 200 plus acs and looked fairly deep at the several places that I checked. The recent dozer work and boat launch area had me thinking it might be worth checking out in the next year or two. I drove into the south and north end of Billy Clapp Lk and don't see anyplace to camp there. Any of the roads that are are on the maps go to the lake where you can camp for the night? I don't see much written up about this lake and have heard there are some nice fish in there. The stocking reports show that they dump a decent amount of trout in there.

the only roads that go to billy clapp are at the north end and the south end. no road on the east or west side gets to any lake access, and the land there is private. no camping is allowed at the north end, as the tiny "summer falls state park" is day-use only. and the WDFW access on the south end is also day-use only. since columbia basin irrigation water flows through billy clapp, the water level fluctuates throughout the year.

Hmmmm, Maybe you've discovered something newly created! Did you say there waz a boatlunch newly constructed on it?? There were several large (but not 200 acres) seepage ponds in that area but none had a boatlaunch on them.
May be worth investigating.

As Big Jon said there is NO Camping at Billy Clap nor anywhere nearby there. In fact the nearest I legal free campground I can think if is back at Alkali, but there is an inexpensive one at Soap lake, just as you first hit the lake going out of town.

The fishing on Billy Clap is a highly guarded secret and mostly hit by locals.
It is fair for Walleye,excellent for Smallmouth,and better than Average for trout though not as good as the plant would lead on to believe ,cause they plant fry and the walleye and bass eat half or more of them.

KENT: i spoke with an irrigation district employee about that "lake." he said it is caused by seepage from the irrigation canal, and that last year when the water in the canal was shut off at the end of the irrigation season, the "reverse seepage" back toward the canal damaged the side of the canal. this year they have been experimenting with pumping water from that "lake" back into the canal, hoping to eliminate damage to the canal this year.

the employee didn't know if there were fish in that intermittent lake or not; it seems to me that if there were, they would have had to "seep" into the lake along with the water.

Thanks John, I finally got a answer back to my e-mail to the WDFW and they said about the same. They did add that they are watching this lake closely and it has held water well the past several years and they are thinking about stocking it in the future. They said walleye and lots of big carp are in there. I was over that way last week and there was more fishing garbage along the lakeshore, so people are fishing it. I found a new area nearby with some lunker trout, so I'll be over there in the next few weeks. If I get time I'll have to try out Trail Lake.