The island is connected by bridge to the village of Conway, located on the east shore of the South Fork of the Skagit River.

A second bridge, across the North Fork of the Skagit River, leads to La Conner, 3.7 miles (6.0 km) northwest.

Near the northeast tip of Fir Island is the site of the 19th-century town of Skagit City which declined after upstream log jams were removed in 1877.

Over the course of a year, 180 species of birds have been recorded at Skagit Wildlife Area, 13,000 acres (53 km2) of mostly tidelands and intertidal marsh, the largest section of which is located on the southern margin of the island.

[7] A number of buildings were carried away by the river, and area farmers lost between 150 and 200 chickens, 4 head of cattle, and 8 or 10 sheep.