If I can catch and keep two fish per day at Henrys Lake and I fish for three days, am I OK to have six fish in possession?

No. The daily limit in Henrys Lake is two trout, including brook trout. The possession limit, however, is the same as the daily limit; therefore the most fish you can have in your possession is two. Parts of the lake are closed to fishing. Check the fishing rules book for additional details.