No, we do not have to worry about concealing our rifles. With that said, we should make every effort to treat them as real rifles and leave them in a gun bag, on a truck bed, in a car, etc so we do not intimidate any hikers, cyclists or have an unusually aggressive law enforcement officer have to respond to a call of people waiving around guns.
The area we park at is technically federal land and is subject to the typical regulations of the Wichita Wildlife Refuge. However, the land we cross into is City of Lawton Public land and is designated for all manner of outdoor recreational activities. Because of this odd combination of parking in the refuge but hiking into public land, even hunters when they bring real firearms are fine so long as they are unloaded at all times on the refuge side.
We have both Wildlife Officers and City of Lawton Police Lake Patrol Officers around before and following the above where we do not mess with our rifles openly until we are ready to head in has proven very effective at keeping all parties happy.
Remember we do hike in about 1/2 to 3/4 of a mile so plan to bring all supplies you need with you, such as extra bb's, batteries, anti-fog spray, and most importantly WATER.