Muir Inlet is the eastern arm of Glacier Bay within Glacier Bay National Park and Preserve in Alaska. This 29-mile-long saltwater fjord is a designated wilderness area closed to cruise ships and most motorized traffic, offering a pristine paddling environment. Access is exclusively by boat or plane. Most paddlers begin their journey from Bartlett Cove, the park's headquarters, after obtaining a free permit required from May to September and attending a mandatory bear-safety session. From there, paddlers typically travel via the park's daily tour boat, which provides drop-off and pick-up services for kayakers at designated points like the Mount Wright area near the inlet's entrance. There are no formal launches or take-outs; all access is via wilderness beach landings from the tour boat or via a multi-day paddle from Bartlett Cove.

The paddling character is defined by dramatic glacial scenery, significant wildlife, and dynamic conditions. The inlet features towering mountain peaks, active tidewater glaciers like Riggs and Muir at its head, and sapphire-blue icebergs. The shoreline is constantly changing as the land rises up to an inch per year following glacial retreat. Paddlers share the waters with abundant marine life, including humpback whales, sea otters, and seals, and must maintain a distance of at least 100 meters from whales. The forested shores are home to brown bears, black bears, moose, and wolves, necessitating strict food storage and awareness.

Key hazards require careful planning and constant vigilance. Calving glaciers and rolling icebergs can generate large, sudden waves capable of flipping kayaks; a minimum distance of a quarter nautical mile from glacier faces is recommended. The tidal range is extreme, reaching up to 20 feet in the late spring, requiring boats to be secured well above the high tide line. Tidal currents are strong, particularly in the lower bay near the Beardslee Islands, and paddlers are advised to plan itineraries to paddle with the flood and ebb tides during prime hours. Wind can funnel down the fjord, creating challenging wave conditions, and paddlers should seek shelter close to shorelines when necessary. McBride Inlet, a branch off Muir Inlet, is noted for dangerous rip currents due to its bottleneck shape and should be avoided. Campsite selection is critical; beaches with a narrow intertidal zone are preferred to avoid long gear carries across extensive, often muddy, silt flats. All camping is wilderness style with no improved sites or facilities.