Science Spotlight

Lake-side signage lets anglers know Kirman has recently been stocked with wild brook trout and asks for help from anglers in competing a brief survey about their fishing experience.


CDFW fisheries biologists electrofish Silver Creek in Mono County to remove non-native brook trout to reduce competition with native cutthroats.


The tremendous amount of aquatic life within Kirman Lake provides a nearly unlimited food supply for transplanted brook trout from Silver Creek and transplanted Lahontan cutthroat trout from Heenan Lake. Kirman itself has no spawning habitat and is dependent on trout plants from CDFW to maintain the trophy trout fishery.


Before release into their new home in Kirman Lake this fall, brook trout were measured and their adipose fins clipped. CDFW scientists plan to track their growth rates with the help of voluntary angler surveys.

It’s a question that has been asked by more than a few eastern Sierra trout anglers: What happened to the fishing at Kirman Lake?

Kirman, a small backcountry lake north of Bridgeport in Mono County, has long been heralded as one of the very few places in the state where anglers could catch trophy brook trout.

While many high-elevation waters hold overpopulations of stunted brook trout measured in inches, the brook trout in Kirman were measured in pounds. Fish in the 2- to 4-pound class were common with numerous reports of brookies exceeding 5 pounds.

The lake requires a moderate, 3-mile hike to reach – just enough distance and difficulty to discourage casual anglers and help minimize some of the fishing pressure, particularly with so many great trout fishing options nearby. The lake is a special-regulations water with limited harvest. It is open to fishing during the state’s traditional trout season from the last Saturday in April to Nov. 15. Only artificial lures with barbless hooks may be used. Only two trout can be kept – with a minimum size limit of 16 inches.

Kirman was a destination known well beyond the confines of Mono County.

Fly fishing author and instructor Denny Rickards included Kirman in his book “Fly Fishing the West’s Best Trophy Lakes.”

Rickards writes, “Those who have made the trek and landed one of these beautiful trout know what a delicate lake it is. Part of the promise here is more than just big brook trout – the lake also harbors big cutthroat. However, the cuts aren’t the primary focus of those who fish here. It’s those big, beautiful brookies that bring fishermen up the trail.”

Author Bill Sunderland likewise highlighted Kirman in his book “Fly Fishing California Stillwaters.” He writes, “The fish here, both brook trout and Lahontan cutthroats from Heenan Lake, grow exceptionally fast. A four-year-old brookie can be twenty inches long and weigh four pounds. Many of them are football-shaped, the result of their rapid growth.”

In recent years, however, the brook trout seemingly disappeared with anglers reporting fewer catches with no brookies in the mix. Fishing reports from Kirman dried up as well at local tackle shops with fewer anglers apparently making the trek.

What happened to Kirman Lake and its trophy brook trout is no mystery to CDFW fisheries biologists, who are committed to restoring the lake to its former glory.

“There’s no spawning habitat,” explained Jeff Weaver, a senior environmental scientist with CDFW who oversees the department’s Heritage and Wild Trout Program. “All the fish in Kirman Lake have been stocked to provide the recreational fishery.”

Brook trout were planted annually by CDFW until 2015 when hatchery problems prevented the raising and delivering of the fish.

What Kirman lacks in spawning habitat it makes up for in food abundance. Unlike many high-mountain lakes where trout eke out an existence in near-sterile conditions, Kirman is the equivalent of a 24-hour, all-you-can-eat buffet. The lake is loaded with all manner of aquatic invertebrates -- water boatman, dragonflies, mayflies and midges – along with high-protein leeches and shrimp-like scuds. The heavy population of scuds accounts for the tremendous growth rate and size of Kirman brook trout.

When Russell Black, CDFW’s new fisheries supervisor for the Inland Deserts Region, learned about the lack of hatchery plants and the poor state of the once-great fishery, he came up with a simple yet creative solution.

This past fall, work was underway at nearby Silver Creek to prepare the water for the eventual restoration of native Lahontan cutthroat trout. CDFW biologists electrofished Silver Creek to remove the non-native brook trout there to minimize competition with the native cutthroats.

Black’s idea: Take those brook trout and transport them to Kirman.

More than 1,300 Silver Creek brook trout in a variety of sizes were relocated to Kirman. Prior to release, the fish were measured and their adipose fins clipped. CDFW biologists encourage anglers at Kirman this upcoming trout season to record their catch and fishing experiences at angler survey boxes lakeside so they can track the transplanted Silver Creek brook trout.

Given the exceptional growth rate at Kirman, CDFW biologists expect anglers to get into some quality fish by the fall.

Even as CDFW shifts its statewide trout hatchery focus to raising and stocking native trout as opposed to non-native brown trout, brook trout or even domesticated strains of hatchery rainbow trout, biologists see a future for trophy brook trout in Kirman and are exploring options to resume annual hatchery stocking.

“Kirman Lake is one of those celebrated fisheries where we weigh management in favor of continuing that recreational fishery,” said CDFW’s Weaver, who himself has fished Kirman a dozen or so times over the past 20 years. “Kirman Lake is managed as a trophy trout fishery and we intend to continue to manage it as a trophy trout fishery. We’ve just been on pause as a result of the lack of stocking.”

The pause may be over, though, as CDFW intends to maintain the supplemental stocking from Silver Creek until regular hatchery plants can resume.

CDFW Photos. Top Photo: This small brook trout was one of many relocated this fall from Silver Creek to Kirman Lake, where it could potentially grow into a trophy-sized fish awaiting anglers this trout season.

Media contact: Peter Tira, Communications, (916) 322-8908

It’s just before dawn in the eastern Sierra Nevada Mountains in Mono County. It’s a cold clear morning, a good day to be out experiencing a still very much wild area of California. California Department of Fish and Wildlife (CDFW) biologist Justin Dellinger and a Wildlife Services houndsman are preparing gear to go out looking for fresh mountain lion tracks in this vast landscape. With the help of a team of highly trained dogs, Dellinger and the tracker are focused on the ultimate goal: Capturing a mountain lion and outfitting it with a GPS collar for research purposes.

This tracking effort in Mono County is part of a larger project to estimate mountain lion population size statewide. It began in the southern Cascades and northern Sierra-Nevada Mountains in 2015, and since then CDFW has solely undertaken or collaborated on similar efforts in the north coast, Modoc plateau and here in the eastern Sierra Nevada Mountains. It’s tough work with long hours; trackers can spend days or even weeks in pursuit of lions. Yet tracking remains the gold standard method of gathering data in the mountain lion research world.

Notably, it takes both biologist and houndsman, each with a unique skill set, to make this team effort work. On this particular day, for example, Dellinger starts the ball rolling when he spots a fresh set of mountain lion tracks made the night before. The mark of the hind heelpad, measuring 52mm across, indicates that it’s a tom (male cat) heading southwest. The long stride suggests he’s traveling in a focused and determined manner – perhaps to secure a meal, locate a mate or confront another male trying to move in on his turf.

Dellinger radios the houndsman, who is astride a mule. The houndsman makes his way to the tracks with dogs in tow, where he assesses a wide variety of information – the time of day, wind speed and direction, topography, etc.

“The mental calculations (of the tracker) are rooted in decades of experience and know-how, but they’re still somewhat of an enigma to me,” Dellinger says. “But then again, houndsman feel likewise about the statistical calculations employed by biologists. It takes both of us, working together, to compile all the information and derive a solid population estimate.”

Over the next several days, the houndsman and the biologist follow the tom over miles of country, with the cat none the wiser about his pursuers. The team eventually catches up to the tom. The dogs masterfully trail him over boulders and around escarpments and tree him in a pinyon pine. The houndsman signals to Dellinger that the tom is treed. Dellinger then works his way into position to dart the animal. Success! Within an hour, the cat is asleep and Dellinger is able to affix a collar.

Yet despite the enormity of the overall effort, the day’s accomplishment is only one small step in the overall plan. Simply put, they’ll get a little rest and then wake up and try to do it all over again tomorrow.

As CDFW’s lead mountain lion biologist, Dellinger understands the need to study and understand Puma concolor only too well. “Lions are the apex predators across much of California, and apex predators can tell scientists a lot about the ecological wellbeing of a given landscape or ecosystem,” he explains. “If mountain lions are decreasing in an area, it’s likely that prey species are decreasing too. If mountain lions are exhibiting health issues, it’s likely that other animals in the ecosystem are experiencing similar issues.”

Because of those grants, this first comprehensive effort to collar lions around the state is now underway. It’s a huge and somewhat daunting task. California’s size and ecological diversity requires a divide-and-conquer approach, meaning that studies can only be conducted in one area at a time. Together, those “slices” of data will add up to a statewide picture. 

Getting the collar on the cat might be the most important part, but all of the data Dellinger collects on this trip will be useful. He’ll be able to compare tracks and remote game camera photos with GPS collar data to derive a minimum count of mountain lions in the area. For now, this is the best way of counting mountain lions in the western United States. In the future, CDFW may grow to rely on data gathering techniques that are more cost- and time-effective than tracking, and use more common skill sets. One possible alternative is developing thanks to the rapid advance of using genetics to monitor wildlife species without having to handle the animals. Scat samples can be collected and analyzed to provide a genetic fingerprint of the animal that deposited them. In theory, if enough lion scat is collected over a large enough area, CDFW can estimate the number of lions in the area.

But scat analysis is still a fairly new way of doing things, and until techniques can be tested, compared and perfected, CDFW will continue to employ the tracking “gold-standard.” The newer methods can be compared to the old, and it’s possible that the newer methods will outperform (i.e., be cheaper and just as reliable) the older methods in some areas but not other areas.

CDFW sees this statewide effort as a first step in monitoring and conserving the elusive, ecologically important mountain lion long-term in California. The project is still in its early stages and will likely continue for another six years or so. Dellinger is enthusiastically looking forward to the work. “It’s really cool because no other state has attempted such a comprehensive population assessment of lions … and  no other western state is as ecologically diverse as California,” he says. “Doing something this comprehensive requires working in a lot of very unique areas. It’s never going to be boring.”

Photos courtesy of Justin Dellinger