The US Army Corps of Engineers (USACE) manages Lake Lanier and operates most of its parks.  Their price of admission is $5.00/per day.  You can save money by buying annual passes to use their facilities and boat ramps.
Annual passes for USACE parks are $40, for example. Â Unless they aren’t $40.
Some parks (not all) have discounted senior citizen passes or free admission … but the age that unlocks such benefits depends on who runs the park.
Active military personnel can get a free USACE annual pass.  If you’re 62 or over, buy an America the Beautiful Interagency Senior Pass (ABISP) for $20 by mail, or for $10 at “an issuing site.”
Persons with permanent disabilities can get an ABISP for $10 by mail, or for free at “an issuing site.”  Anyone who volunteers 250 or more hours annually at select parks is eligible for the America the Beautiful Interagency Volunteer Pass.  Children in 4th Grade get free passes too.
Other parks on Lanier are operated by Forsyth County or Dawson County or Hall County or by the City of Gainesville.  One is run by the State of Georgia.  At times, different organizations loan out parks for other agencies to operate.  (Honest.)  Please contact them for exact admission prices.
Is it true I have to renew my Senior Lifetime pass every year? How do I know when to renew it?