Marathon Helicopters operates different tours during the summer season, with various activity levels and lengths. Tyler and I have only done their 5 minute ride over the town of Seward (a special they have on the 4th of July) and it was incredible, so I can only imagine how breathtaking their tours over the glaciers and mountains of Kenai Fjords would be like. It's one of the more expensive excursions in Alaska, but it's worth it.