Modern-day techies and millennials would be aghast if they didn’t have 4G LTE technologies to provide IP-based voice, data and multimedia streaming services to run their smartphones, tablets, netbooks, notebooks, and wireless hotspots. Colorado anglers, on the other hand, are perfectly happy with 2G- Rifle Gap and Harvey Gap reservoirs that is.

Fishing for predators is rarely easy, but difficult conditions can make it even tougher. With the water levels extremely low and clear from irrigation withdrawals on Rifle Gap, calm winds and a bright September sun the odds were stacked against guide Connor Foy and I catching any walleyes. It didn’t help that the drive across I-70 had taken longer than expected and it was nearly mid-morning by the time I arrived. Fortunately, our target wasn’t walleyes, but the jumbo perch Rifle Gap was famous for. Perch are sight-feeders and bite quite readily during the midday hours.

Foy spotted my Lab, Sam, and I waiting on the end of the dock and pulled anchor to come over and pick us up. I apologized for my tardiness. It was an incredible Indian summer day. Connor knew of some brush piles that usually held perch schools when the reservoir got extremely low and clear. Rifle Gap gets a fair amount of fishing pressure too and when pressured, panfish retreat into the available structure.

Unlike Harvey Gap, high-speed boating is allowed on Rifle Gap and the splendid weather had brought out a bevy of water zealots that were determined to whip the water to a froth. The activity forced the fish even deeper into cover.

Foy pointed out some clumps of brush on the graph that was our target. Normally, you’d anchor and allow the boat to swing over the cover, but with no wind, Foy elected to just use the trolling motor to position us. The terminal set up Foy used was an ultra-light version of a drop-shot rig. It involved light 2-pound test line, a round ¼ oz. tungsten weight and a tiny, No. 14 light wire fly hook with a straight eye. Foy added a sliver of shrimp for bait. It was stealth rig designed for tempting pressured panfish in clear water.

Foy and I cast our rigs to the brush revealed on the graph. The theory was the drop-shot rig would keep the bait above the limbs and minimize snags, but allow us to fish in the junk where the fish had retreated. With the sensitive graphite rods and light line, you could feel the sinker hopping through the branches as you lifted and dropped the bait.

One cast I felt the rig get snagged and I gave it a hard pop to try and free it. Something pulled back. I played the fish gingerly on the light line and frail hook and after several seconds a brilliant yellow jumbo perch came rolling to the surface. The orange-finned and maize-colored yellow belly was a classic example of the kind of perch Rifle Gap were famous for.

“The most recent data I have available on Rifle Gap shows multiple age-classes of yellow perch, including a pronounced age-class in the 8- to 10-inch range and a less pronounced age-class in the 12- to 14-inch range,” said CPW Grand Junction Area Aquatic Biologist  Ben Felt. “Of course, there are always going to be more small individuals than large, but the data we gathered last year did show a healthy population size structure with the presence of multiple age-classes, including a decent number of “jumbo” perch.”

The brush pile also produced a couple of saucer-shaped bluegills. The ‘gills were pale in color, but their backs were an aqua blue that mimicked the hue of the water perfectly. Small perch attracted our rigs relentlessly after that. We moved to a couple of other spots, but couldn’t evade the tiny, pesky perch.

“Although these smaller perch can be a nuisance, especially when they keep folks from hooking into the larger fish, I think the abundance of these smaller fish is an encouraging sign for the future of the perch fishery and represents a solid spawning year or two rather than a true “stunting” of the population,” said Felt. 

We decided to try trolling now that the wind had picked up slightly.

The deeper water along the face of the dam held numerous large predators as revealed by the graph, but they were having none of it. The boat traffic, bright sun, and clear water conditions made it tough to fool the reservoir’s pike, walleye and bass.

As luck would have it the wind increased and changed direction now blowing directly into the opposite shoreline. The exposed shoreline there began getting pounded by the building waves and before long a mud line was created that began rolling back out into the reservoir. We’d marked huge clouds of baitfish there that we assumed were perch. Foy had an idea. We replaced the trolling lures with blade baits that we intended to work vertically in the now cloudy water. The small perch were so thick that we occasionally hooked them on our lures. Every once in awhile though we could see big hooks on the graph mixed with the perch.

            Soon Foy let out a grunt and announced, “Fish!” as his rod bent double. We both peered over the side trying to see exactly what was on the other end of the delicate line in the murky water. After a few seconds, a good-sized northern came into view and I scooped it up with the net. The pike were taking advantage of the cloudy water and better hunting conditions. Several more northerns harassing the perch schools crushed our blade baits before we decided to call it a day.

           Colorado Parks and Wildlife has been taking steps to disadvantage predators such as fertile walleye, smallmouth bass and northern pike in Rifle Gap Reservoir to indirectly bolster the survival of endangered native species downstream in the Colorado River. These steps include encouraging angler harvest of these species (no bag limits), as well as the removal of targeted diploid (fertile) walleye and incidental smallmouth bass and pike, from the reservoir. The three-year removal project for fertile walleye and ongoing removal of incidental smallmouth bass and northern pike are, designed to prevent escapement of the predators into the Colorado River where they could impact native endangered species.

            “I don’t think it is necessarily a matter of walleye being potentially more detrimental than northern pike would be in the river,” speculated Ben Felt on why the removal was focused on walleye. “Both are extremely predatory and are a significant threat to native fish in the Colorado River if they were to escape out of Rifle Gap and establish in the river. The reason we chose to conduct the walleye removal project on Rifle Gap was part of the agreement in the Lake Management Plan ( https://cpw.state.co.us/Documents/Fishing/RifleGapResMgmtPlan.pdf), which allows us to stock sterile walleye moving forward as long as we also made an effort to suppress the fertile population.  Basically, the idea is to transition the walleye fishery from a fertile population to a sterile population through the stocking of sterile fish and removal of fertile fish.  This would allow continued angling opportunities for walleye for anglers while also protecting native fish in the Colorado River should some of these sterile walleye make it past the fish screen on Rifle Creek.”

           “CPW is conducting a three-year project focusing on removal of fertile, gravid, female walleye that will conclude in 2019.  The project is being conducted in order to allow the CPW to stock sterile triploid walleye (109,000, 1.2-inch triploid walleye fingerlings have been stocked since 2015) and black crappie (17,800 1.3-inch black crappie fingerlings have been stocked since 2014). The project will enhance our ability to stock species other than trout,” claimed Felt. “The last year of the fertile walleye removal project is 2019 coinciding with the length of time that stocked sterile walleye may be of a size to be captured in gill nets by CPW biologists.” Survival levels for walleye fingerlings are typically low. Kingfishers, dragonflies, the burgeoning perch population and a host of other predators prey upon the diminutive fingerlings.  

            “You are right that gill nets are indiscriminate in the sense that they will effectively capture any fish that encounters them.  The good news is we are able to reduce by-catch in these gill nets by just targeting the dam area and only during the walleye spawn.  The timing and location of these nets are specifically targeted at fertile walleye, which results in the majority (83.3% in 2017 and 71% in 2018) of fish encountered being walleye,” stated Felt. “We do remove northern pike and smallmouth bass during these efforts, but those numbers are very small (7 northern pike in 2017, 7 smallmouth bass in 2017; 25 northern pike in 2018 and 8 smallmouth bass in 2018) because of our efforts being targeted at walleye.”

            The basin-wide nonnative aquatic species prevention and control strategy document states that the “stocking of approved sterile fish species in specific locations equipped with screens or otherwise managed to prevent fish escapement would provide redundancy and a more preventive strategy to control the access of these non-native fish species to critical habitat for endangered fishes.”  

             In the spring of 2013, CPW completed the construction of an in-stream fish screen in Rifle Creek downstream of Rifle Gap Reservoir’s stilling basin. The intent of the screen is to preclude non-native sport fish that may escape from Rifle Gap Reservoir, from negatively impacting native, listed and non-listed fish species downstream in critical habitat of Rifle Creek and the Colorado River. The Rifle Creek fish screen is operational and functioning successfully by eliminating the opportunity for non-native sport fish to negatively impact native, non-listed and listed fishes downstream.

            CPW manages lower Rifle Creek and the Colorado River downstream of the town of Rifle for native fish, including listed and non-listed species that include bluehead sucker (Catostomus discobolus,) flannelmouth sucker (Catostomus latipinnis), roundtail chub (Gila robusta), and speckled dace (Rhinichthys osculus.) The U.S. Fish and Wildlife Service (USFWS) has designated the mouth of Rifle Creek and the main stem Colorado River immediately downstream of Rifle Creek as critical habitat for two of the four endangered fish species, including the razorback sucker (Xyrauchen texanus) and Colorado pikeminnow (Ptychocheilus lucius).

An outstanding recreational fishery also exists on Harvey Gap. “Harvey Gap is quite a bit different than Rifle Gap in the sense that escapement of non-native fish is not as much of a concern because all of the water leaving the reservoir dead ends on fields and can’t make it to the river,” shared Felt. “The fishery itself and management strategy is also quite a bit different in Harvey.  We (CPW) are managing Harvey Gap for largemouth bass, yellow perch, black crappie, bluegill, channel catfish, tiger muskie, and trout. We had a couple of projects on Harvey Gap this year to improve the fishery. We installed some habitat structures and also moved some largemouth bass from a nearby municipal pond closed to the public to try to provide some additional angling opportunities.” 

Motorized boating was not allowed on Harvey Gap in 2018. ANS inspections use different funding sources than reservoir surveys. “The ANS program lost much of its funding following a successful lawsuit filed by BP America Production in 2016 which required the refund of millions of dollars in severance taxes and largely defunded the statewide ANS program.  Ultimately, it was Silt Water Conservancy District and CPW’s decision to not allow trailered watercraft on the reservoir without an inspection,” added Felt.

Without a boat, I reasoned my next best option was my float tube. I hadn’t used the tube in years, but it seemed like a good option for getting away from shore and covering more water. I saw some structure not too far out from shore. I realized that what it was seeing were the fish structures that had recently been placed in Harvey Gap by CPW. Even though they hadn’t been there long, I reasoned they might have still have attracted fish.

I resembled a wounded duck as I awkwardly walked backward with my flippers and tube into the water. Fortunately, no one was around to see me fall. It finally got deep enough for me to sit down. The reservoir was flat calm and reflected a clear azure blue. The cool water felt good and would be a welcome relief from the sweltering day that was promised. I only had to go about 40 yards out before the bottom disappeared and in order for my casts to reach the first fish hide. I threaded part of a nightcrawler onto a small jig head under a float and cast it toward the structure. My bobber went down instantly. I set the hook and felt the bulldogging pull of a bluegill. The ‘gill was decent size, but I wasn’t sure how many I might catch. Enough for a fish dinner?  I questioned my good fortune and gently released the fish. The next cast produced a red-breasted bull bluegill and I cursed myself for not keeping the first panfish. Subsequent casts produced a bite every cast, but most of them were tiny perch again. I finally caught a respectable crappie to add to my catch.

“Quite a bit of work has gone into getting permission to install these structures and also to install and maintain the structures. This was a great collaborative project between CPW, Silt Water Conservancy District, and local anglers to address the lack of structure in the reservoir and increase the growth and survival of smaller-bodied fish species in Harvey Gap,” shared Felt.  For more information visit: http://cpw.state.co.us/Lists/News%20Releases/DispForm.aspx?ID=6495

Larger fish boiled the surface with regularity around the structures and I decided to cast a stickbait to see if I could interest them. Reasoning they were probably busting the small perch, I put on a deep diver with a perch finish. I’d only made a couple of casts when something thumped my vibrating crankbait. A hammer-handle northern came quickly thrashing to the surface. I deftly flicked the treble out of the corner of his jaw without injury to either party. Twin 20-inch pike smacked the crankbait before the sun started to beat down signaling it was going to be another sweltering late-summer day on the Western Slope.

Both Harvey and Rifle Gaps offer both anglers and nature lovers spectacular views, pristine waters, and outstanding angling opportunities. The reservoirs have been known to produce exceptional angling for walleye (at Rifle Gap only) pike, bass and panfish.

“CPW has actively monitored and managed these fisheries for decades and is well aware of the “delicate balance” that exists between fish populations in these reservoirs and will continue to manage these reservoirs to provide that balance for a diversity of angling opportunities.  Following the approval of the LMP, CPW is now better equipped to manage the Rifle Gap fishery through the stocking of cool/warm water fish species,” announced Ben Felt.

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