Oct 2, 2026
FWP Samples Fishery at Nelson Reservoir
Montana Fish, Wildlife & Parks Region 6 fisheries biologist Cody Nagel and technician Dawson Schott sampled the fishery at Nelson Reservoir in Phillips County over a three-day period the week of September 21st. The gill netting effort is part of the long-term monitoring FWP has conducted at Nelson Reservoir for decades. Gill nets with variable size mesh were set overnight to get a snapshot of the species composition, relative abundance of those species and size structure of the fish populations.
Nelson Reservoir is known for its excellent walleye and yellow perch fishing during both open water and ice seasons. To better understand age and growth of the walleye population, Nagel and Schott removed otoliths from walleye and will age those fish during winter in a laboratory setting. Otoliths (ear stones) lay down rings as fish grow and when properly prepared can be read like growth rings in a tree.
These data give biologists a good understanding of how fast fish are growing, what age sexual maturity is reached and the longevity of fish in a system. FWP can then compare growth rates between years where forage may be more or less available, and also contrast growth rates between years with differences in walleye abundance.
Although the data haven’t been worked up yet (there is still a lot of field season left to collect more data), the preliminary data from the sampling effort indicated that walleye abundance has increased from last year and is near the long-term average in Nelson Reservoir, and the walleye observed are also robust in stature (good weight:length ratio).
On the flip side, the netting didn’t produce many yellow perch, which would indicate that population is below the long-term average in 2026. Thankfully, the yellow perch population can fluctuate significantly within a given year and has the potential to come back strong if environmental conditions lead to good spring spawning success and recruitment. Nelson is an excellent yellow perch fishery and although it may be below average this winter, it is still one of the premier perch fisheries within Region 6.
Nelson Reservoir also has relatively good numbers of other game fish such as black crappie, northern pike and smallmouth bass as well as less common fish like lake whitefish and pumpkinseed sunfish. As for native non-game fish (which are also fun to catch), Nelson Reservoir is home to shorthead redhorse, white suckers, smallmouth and bigmouth buffalo, goldeye and possibly more.
So, while the weather is nice, get out and enjoy this fishery while it is still open water, and then get ready for cooler temperatures and ice fishing this winter!
