Rangers are encouraging humans to keep their distance from the birds, which have set up housekeeping high in a large tree. Pedestrians have been banned from the railroad tracks near the nest, and signs posted on a hiking trail urge walkers not to linger near the nest, The Cleveland Plain Dealer reported.
A pair of bald eagles nested in the same area in the park last year but produced no eggs.
Mary Pat Doorley, a spokeswoman for the park, said the birds appear not to notice the chuffing trains of the Cuyahoga Valley Scenic Railway.
"It's a real exciting time for the park," said interpretive ranger Paul Motts. "It just shows our great efforts in trying to preserve areas like this."
The park is along the Cuyahoga River and the Ohio and Erie Canal between Cleveland and Akron.
Bald eagles, like many other birds, came close to extinction because of widespread use of the pesticide DDT, which caused their eggs to have thin shells. DDT was banned in the 1970s after Rachel Carson wrote her classic book "Silent Spring."