Marco sits at the western door of the Everglades, which is a genuine geographical advantage and a persistent source of booking confusion. The eastern side of the system, the one most people picture, is sawgrass prairie with airboats skidding across it, and it is reached from Miami. The western side — the side you are on — is where that same slow sheet of fresh water finally reaches salt, spreads out through a hundred thousand acres of mangrove and empties into the Gulf through the Ten Thousand Islands. It looks nothing like the postcard, and it is far closer.
The practical distances from the Jolley Bridge are worth memorising before you book anything. Collier-Seminole State Park is about twenty minutes east on US-41. The Ten Thousand Islands refuge's Marsh Trail, with its two-storey observation tower on the south side of the highway a few miles west of Port of the Islands, is around thirty. Everglades City and Chokoloskee are roughly 35 miles, call it 45 minutes via San Marco Road and US-41. Shark Valley, where the tram and the bike loop are, is closer to two hours. Flamingo, at the park's southern tip, is most of a day each way. A tour that leaves from Marco and promises the Everglades is almost always working the first three of those.
Something significant changed on this side recently. The national park's Gulf Coast facility at Everglades City was wrecked by Hurricane Irma in 2017 and operated out of temporary arrangements for years afterwards. Its replacement, the Marjory Stoneman Douglas Visitor Center, is now open — a raised, heavily engineered building with its own marina and kayak launch, open daily from 9am to 5pm. Park entrance passes are not sold there, so buy online before you drive out. The concession boat trip into the Ten Thousand Islands has been running from a temporary dock on Dupont Street during the transition and moving to the new park marina, so confirm the departure address when you book rather than trusting an older listing.
The other thing worth stating plainly: there are no airboats in the national park on this coast. The three airboat operators authorised to run inside Everglades National Park sit on the Tamiami Trail far to the east, much closer to Miami than to here. Airboat rides sold on Marco Island either drive you a long way east, or run on private land and water outside the park boundary. That is not a scandal — plenty of them are good — but "Everglades National Park airboat tour" and "airboat tour near the Everglades" are different products, and the price difference rarely reflects it.
What the western side gives you instead is water. Mangrove tunnels, oyster bars, dolphins in the river mouths, manatees in winter, ospreys on every marker, and a horizon of islands. It is quieter, greener, and much stranger than the sawgrass version.