Winter Fishing Season Update

Friday, May 20, 2016 - 4:15pm


James Chandler



           Eighteen weeks ago I began monitoring the two new open sections of the Henry’s Fork, from Vernon Bridge to Ashton Dam and from the northern side of Riverside Campground to the southern border of Harriman Sate Park.  Since then I have counted, observed, and talked to many anglers who braved harsh weather and enjoyed some of the first warm, sunny days on the river in Ashton.  Now that it is May, three of the four monitoring periods within my angler use survey are complete.  We have seen a dramatic increase in the number of fishermen out on the river since those cold, short days in January.  It was once unusual to see more than four or five people in a day; now it is odd to see less than ten.  To better illustrate this progression I will review the numbers from the first periods of the study and present our most recent findings.  It is important to note that the following data reflects only the fishing at the section in Ashton and not at Pinehaven. 

            During the first period, mid-winter, which lasted from January 16th to February 12th, there were twenty possible weekdays and eight possible weekend days that people could have fished.  During those days there were 162 fishable hours during the week and 64 on the weekends.  Based on our observations, we estimated anglers invested 51 angler-hours during weekdays over the duration of the period.  The weekend effort for the period was 40 angler-hours.  If we break that down further it equates to 2.5 angler-hours per every week day and 5 angler-hours per each weekend day.  For those people who braved the elements and battled frozen line guides to fish in January, they had the luxury of having the river to themselves. 

            The second period, late winter, began on February 13th and finished on April 1st.  This period was not only longer but also saw warmer days, and more fishermen.  During this period there were 34 weekdays and 15 weekend days.  There were 320 fishable hours during the week and 138 on the weekends.  Weekday effort more than tripled during this period, with 175 angler-hours estimated, and quadrupled on the weekends with 162 angler-hours.  With the increased effort we saw a large rise in the estimated number of fish caught between the mid- and late-winter periods.  During the first period we estimated that 44 Rainbow Trout were caught.  In the second period that number jumped to 164.  Similar trends were seen with Mountain Whitefish and Brown Trout.  At the end of the period we observed a catch rate of 0.8 fish per hour, a rate that includes all species.

            The third period, early spring, began on April 2nd and concluded on April 29th.  The number of fishable weekdays in this period was 20 and the number of weekend days was 8, just as in the first period.  Again, we saw an increase in the angler effort on both the weekdays and the weekend, but most notably during the week.  During this period we estimated 427 angler-hours for the weekdays and 261 on the weekends.   On a daily basis this equates to 21.4 angler-hours per day on weekdays and 32.6 angler-hours on weekend days.  In the third period, fishing pressure was 8.5 times greater on weekdays and 6.5 times greater on weekends when compared to the first period.  The overall catch rate for all three periods was 0.7 fish per hour.  This is slightly lower than the 0.8 fish per hour at the end of the second period, a result that is likely due to the overall increase of fishing pressure.  One reason that increased pressure could decrease the hourly catch rate is because there is more competition for the finite number of fish in the river. With more anglers fishing to the same fish, each angler’s hourly success is bound to decrease. However, the increased effort more than made up for the slight decrease in catch rate. The estimated number of fish caught during the early spring period was substantially greater than in the previous periods, simply because of the increase in fishing pressure.   We estimate that 334 Rainbows, 86 Mountain Whitefish, and 50 Brown Trout were caught during the third period.

            With two weeks left in the new season we are continuing to see an increase in the number of people fishing on the Vernon Bridge to Ashton Dam section. 

In the Pinehaven area, after four and-a-half months, I finally observed and interviewed one angler who was fishing from Wood Road 16.  With summer weather and hatches fast approaching, I fully expect to see more people fishing in the Pinehaven section over the next 10 days, but that stretch did not see any fishing pressure for the vast majority of the newly opened season. 

           The Ashton section, as clearly demonstrated from our findings, received consistent fishing pressure from the beginning of the season, which will likely help to reduce the opening day pressure observed there in previous seasons. Furthermore, the opportunity for winter fishing between Vernon Bridge and Ashton Dam most likely removed some fishing winter fishing pressure that would have otherwise occurred on other reaches of the lower Henry’s Fork.