Tiger Muskies in Merwin Lake

The water temperature is more or less uniform temperature to a depth of at least 30 feet; this lake does not have Mayfield Lake’s sharp temperature gradient, and tiger muskies often are found deeper here than in Mayfield Lake. The surface water temperature can reach the 70s in summer, and cools to 62 degrees in mid-October, by which time the tiger muskies are no longer fishable.

Nearly all of the shoreline is undeveloped, and will remain so because it is owned by the power company and managed for wildlife habitat pursuant to the operating license and agreements with government and tribal entities. In addition, there are numerous legally protected archaeological sites (of ancient Indian villages) in the immediate vicinity of the reservoir, therefore no boat camping is permitted anywhere on the shoreline. Much of the shorelineis bordered by forested hillsides, and many trees fall into the lake. There is a vast array of submerged stumps and logs along the shorelines, and much of the bottom over the littoral zone where tiger muskies are found is a jumble of rotting stumps and jackstrawed logs. At times, the surface is littered with floating logs and wood debris, which is a navigation hazard when present. The lake has a 40 mph boat speed limit, and is regularly patrolled by the Lewis County Sheriff’s Department marine patrol.

The lake and its environs sport some colorful lore. Federal authorities believed airplane hijacker D. B. Cooper bailed out over the lake, and the lake bottom in the vicinity of the dam was searched for his body. In addition, sasquatches are alleged to inhabit the surrounding hills and hollows.

Merwin Lake received its first plant of tiger muskies in 1995, and fish exceeding 30 lbs. are known to exist here. As in most Washington lakes, the fishery is dynamic; that is, constantly changing. Even if I was willing to disclose where my “spots” are, it wouldn’t do you much good, because this changes every year. In 2004 and 2005, I caught most of my fish in shoreline cover, but they disappeared from the shorelines in 2006 and I caught nearly all of mine by fishing the dropoffs. The number of fish my party saw in 2006 plummeted from previous years, raising a question as to whether the tiger muskies have eaten out much of their food supply and suffered a population crash. They may have reduced the squawfish by as much as 90%, and there is little evidence they feed on the lake’s abundant kokanee. It also stands to reason that as tiger muskies grow larger, they need more food, and the lake’s food supply can support fewer of them. If the population is declining in tandem with a shrinking food supply, then we should find dead muskies, and in fact we were indeed finding numbers of dead muskies on the bottom in the 2006 season, which would seem to confirm this hypothesis. However, I’m not a biologist and I may be wrong on all of these counts. Based on my own fishing experience, this is not as good a lake as it was a couple years ago, and the tiger musky population does appear to be thinning out. Harvest may also be a factor, as Merwin Lake’s tiger muskies are now receiving considerably more fishing pressure.

Jim Bradley's tiger:

great report Kalli. It would be cool to catch one of those..and a bag of money and get a picture of Sasquatch. That would be a succesful weekend.

Is this the Lake Merwin north of Vancouver WA?

Is this the Lake Merwin north of Vancouver WA?

Yep.

YEp.  Merwin (Lake) Reservoir (4,090 acres): This North Fork Lewis River impoundment located near the town of Ariel is shared by Clark and Cowlitz counties, with 2,400 acres in Clark County and 1,690 in Cowlitz. Landlocked coho salmon and kokanee are the main target. Angling is best in early spring, with fish in the 10-inch class. Small northern squawfish can be numerous and pesky. Tiger muskies were planted in 1995 to help control squawfish populations. Be sure to check the current reg for size limits.

Muskie Overview by Don Wittenberger:

Merwin Lake is a hydropower reservoir located about 35 air miles northwest of Portland on the North Fork of the Lewis River, which flows 93 miles from Mt. Adams to the Columbia River. The lower reach of this river is an important migratory salmon and steelhead stream and endangered bull trout inhabit portions of the watershed, including Yale and Merwin lakes. (The bull trout can’t reproduce in Merwin Lake, but some come down fromYale Lake above.)