We met guide Mark Franko at the boat launch. The morning was overcast at Diamond Valley Reservoir May 22, with a chill more like March than May. We boarded his 22-foot pontoon boat, and he showed us some shad minnows in his bait tank.

"These may come in handy," he said. "But we're going to start out by trolling with downriggers and maybe with lead core line, with these little Lure Jensen Needlefish."

We didn't have to go very far to find fish. They were right in front of the "Insinuator," a long mooring dock anchored a couple of hundred yards out from the spacious cement boat launch. We could see ???em on his fish finder, right under the meatballs of shad. Several dense schools of minnows cruised along the Insinuator, along with the marks under them that indicated trout and bass.

Mark, a licensed, bonded and insured guide, showed us how to put the tiny jigs behind the cannon ball weights, and dropped two rigs down. We proceeded at slow troll, and didn't go a hundred yards before we had a biter and a hooked trout. The trout was about a pound and a half, and sleek with good feed.

"This is just a little one," said Mark. "We get ???em a lot bigger, up to four, five or six pounds."

We caught and released several more trout of up to two pounds, which slammed the trolled lure almost hard enough to pop off the outrigger clips. The rainbows showed a good preference for a Needlefish in black and white. Mark called it "the cop car."

Then we got a three pounder. It took the cop car, fought hard, and pulled drag off the little left-handed reel. It was a fat fish, with a small head, deep body and as large tail.

Mark added a lead core outfit to our trolling spread, and it produced another three-pounder at six colors.

The cold south breeze died, and we caught a couple more trout of two to three pounds.

"This is fun," I said to Mark. "I haven't had this kind of trout fishing for 30 years."

"This lake is amazing," he said. "I've been on it since it opened, and I'm still learning how to fish it. It's big, with over 20 miles of shoreline, and it's deep. It's supposed to be 240 feet, but I've found some spots closer to 280. It's clear, clean and has plenty of feed."

We came up to another boat.

"That's my deckhand," said Mark, "Matt Thompson. He works with me a couple of days each week.

Matt and his buddy Sean Colt boated a pair of trout while we watched. They were even larger fish, of four or five pounds.

"Wow," I said. "You guys got those on the flyline?"

"With a little split shot," said Matt. "Look at these."

He held out a pair of stripers of 13 and 15 pounds, caught in another part of the lake, earlier, the same way.

"We're gonna try that method next," said Mark.

He produced some ultralight Shimano spinning outfits, with one and two-pound fluorocarbon line. The breeze warmed, out of the east, and the cloud layer was breaking up.

"This day just keeps getting better," I said.

"I just love this lake," said Mark. "It's really made my business better. Look into the water. You can see at least 15 feet."

We put shad on tiny number eight Owner hooks from Mark's tackle box, added a small split shot and cast out. The baits hadn't sunk but 30 or 40 feet when we had a double hookup on bigger fish. It took about ten minutes to bring the pair of four-pounders to the rubberized landing net, because the trout kept making long runs.

"They fight like yellowtail or bonito, don't they?" said Franko. "When they get up on the surface, with the tail and dorsal out of the water, they look just like bonito."

"They look like steelhead to me," I said. "I used to fish trout when I grew up in Oregon, but I didn't catch very many of this size."

The day grew warm as the sun burned off the clouds. I took off my jacket and enjoyed each drift, and caught a trout on just about every bait I cast. We kept about a half-dozen for dinner, and released at least two dozen. The trout just kept getting bigger.

There were a few more little ones of two pounds or less, but most were over three pounds, and some were over five pounds. I got a couple of those on one-pound line, and that made for some serious fish fighting. The light rods bent hard, and the trout peeled off on long runs. One jumped at least four feet out of the water. Occasionally we saw a fish busting the minnows on the surface nearby.

We caught a couple of bass, too. They weren't large, but they were feisty and determined. One of them spit up a dozen minnows. We saw mallards, western grebes and gulls nearby, but only one cormorant. We talked with two anglers who had caught sizable channel catfish next to the Insinuator. The cats were eating shad as well.

One of the anglers, Keith Thomas, is a regular and an expert at catching the shad. He had a channel cat and some big black crappie to go with his trout.

"We've got some really big bluegill in this lake," he said. "Some are over two pounds."

We fished through the lunch hour without even thinking about eating. We stayed busy baiting, retying hooks (Franko will cut off the hook rather than handle a trout) and fighting three to five-pound rainbows on one and two-pound gear. If it wasn't trout heaven it was at least the gateway, I thought.

The next hour was warm and breezeless. We weren't drifting much, so I tried fishing with dead shad sinking them and then lifting and dropping them. Several times I reeled slowly and drew strikes that way, too. These strikes weren't very hard; I could barely feel the trout take the bait, but when I set the hook I'd feel the weight of a big trout, and then the rip of line off the little reel as the trout departed, pulling draw. I was actually getting tired from pulling on the great rainbows.

Mark spent over ten minutes on a trout that looked to be over six pounds. He was elated.

"This one may be a personal best," he noted. "It might go seven pounds! The lake record is about ten."

The southwesterly breeze broke through the calm on the lake.

"That wind will probably pick up," said Mark. "When it does, you have to go back to trolling, because the drift is too fast."

We called it a day at 1:45. It was one of the best days I've ever spent on the water, fresh or salt. We had willing fish, big willing fish, the comfort of the pontoon boat and the savvy of a guide who had a good knowledge of the place and situation. I'd heartily recommend Mark Franko as an outdoorsman who knows how to catch fish, and how to treat and release them.

"This lake is still kind of a secret," said Franko when we shook hands back at the boat launch. Diamond Valley Lake is too good and too big to stay that way, however. To me, it looks like the best combination of engineering and biology ever completed in southern California, and I look forward to fishing there with Mark Franko again.

To contact Mark Franko about guided fishing trips on Diamond Valley Lake or other southern California lakes, call him at (909) 798-0535, or contact him at troutchaser1@msn.com Diamond Valley Lake is owned by the Metropolitan Water District of Southern California. Here's how to contact the marina store: (800) 590-LAKE for rentals, storage, tackle store and market; or go to their site at www.dvlake.com