Thank you all for your input. We have had contact with Lone Rock Boat Rentals and have made arrangements to rent 3 of pontoon boats for about 30 or so people headed to Rainbow Bridge from the Page end, and another boat or two from Halls Crossing.
As such, July 13, 2024 will be Maggie Johnson Lyman Day at Rainbow Bridge National Monument. She is one the few women to visit the Rainbow in the early years of the Monument, and she's the first non-native woman from Utah to see it at the age of 13, one hundred years ago.
One interesting part of the story of the trip was when they crossed the San Juan River. Grandma's dad, Zeke, told her to just hold on the horse's tail and it would take her across the river. However, the river current was strong that day and just as she was about to lose her grip of the horse's tail, Zeke grabbed her hand and he and his horse took her the rest of the way across. She said she was like a flag flapping in the breeze and never touch bottom because of the movement of the horse and the river current.
Here is an early picture from the North end of the Lake with Grandpa Zeke, and pictures from my first trip to the bridge, 1964. That water was tasty and oddly we had a beaver walk past us going down the canyon as we hiked up.