The Obama administration and Republican lawmakers have vastly different ideas about what to do.
Areas of agreement include lifting the price of the $10 lifetime park pass for seniors to $80 and enacting a lodging tax for those who stay overnight, though how much and whether it should apply to campers as well as hotel guests, will have to be worked out in the months ahead.
Republicans point to Congress's appetite for adding new units to the parks system, diluting the pot of federal dollars into ever-smaller slices.
Congress is just beginning to take a closer look at the administration's request for more money and the debate will extend well into 2016.
In a recent hearing, Republican Sen. Lisa Murkowski, chairman of the Senate Energy and Natural Resources Committee, called the backlog a travesty, but she said that spending $1.5 billion without identifying how most of that money would be raised was troubling.
Obama has upped the ante, calling for federal spending of up to $100 million over each of the next three years to be matched with private contributions from individuals, foundations or businesses.
Roads and bridges make up about half of the maintenance backlog, and administration officials will use the recently passed highway bill to direct more money there.