The Blackwater River in Collier County flows through the mangrove-dominated wilderness of southwestern Florida, originating within Collier-Seminole State Park and meandering westward through dense mangrove forests toward Blackwater Bay and the Ten Thousand Islands. This tidal river system presents a distinctly different character from Florida's Panhandle rivers, with dark tannic waters winding through one of the largest mangrove swamps in the world.

The primary paddling opportunity exists as a 13.5-mile loop trail that begins at the boat basin within Collier-Seminole State Park. The first half-mile follows a wide man-made channel before entering the natural river corridor, where red and black mangroves create an intimate canopy overhead. The upper sections narrow considerably as they wind through the mangrove forest, while the lower portions open into tidal creeks and bays including Mud Bay, Royal Palm Hammock Creek, Palm Bay, and Blackwater Bay. A shorter 6-7 mile option to Mud Bay provides an introduction to the system without committing to the full circuit.

Paddlers should possess basic skills and moderate physical conditioning, though the easy-rated trails accommodate beginners. Tidal influence significantly affects the experience—Mud Bay becomes impassable at low tide, and timing trips to high tide (approximately two hours later than Gulf predictions) proves essential. Smaller kayaks and canoes navigate the narrow mangrove tunnels more effectively than longer vessels.

The dry season from November through April offers the most comfortable conditions with reduced mosquito activity and milder temperatures. Wildlife viewing opportunities include roseate spoonbills, dolphins (particularly during incoming tides), manatees, alligators, and various wading birds. The surrounding preserve supports imperiled species within its blend of temperate and tropical plant communities, including one of only three original royal palm stands in Florida.

Access centers on Collier-Seminole State Park along the Tamiami Trail (US 41) east of Naples. The boat basin features launch facilities, restrooms, picnic pavilions, and equipment rentals. A primitive camping site at "Grocery Place" on the river requires advance reservations for overnight trips, though most paddlers complete the trails as day excursions. The river connects to the broader Ten Thousand Islands system, with experienced paddlers able to extend trips seven miles downstream to explore coastal mangrove islands. Filing a float plan remains mandatory for all paddlers using the trail system. The park's historical significance includes its role in preserving Everglades ecosystems and its connection to the construction of the Tamiami Trail, which opened this remote region to modern access.