Great time to be there, bring a 2 or 3 weight rod. Should see some great dry fly fishing for Colorado green backs! Western side of the park will be the best. Kirks is a great shop they will fill you in, contact them now. You have the big thompson coming out of Estes. and close to the North fork of the South Platte. Mostly private but great fish! On the west side of the park you will come out on I-70 you can fish