Seward is the threshold to the park. Exit Glacier is 13 miles from the town by road; the Kenai Fjords National Park Information Center is at the Seward Small-Boat Harbor; and the tour boats that visit the park leave from Seward.
Some visitors try to see the park in a day, coming from Anchorage by train or road, touring the park by boat, then returning that evening. I do not recommend this. To really get to the park, you need to be on an all-day boat trip -- most half-day trips barely leave Resurrection Bay and hardly see the park proper. More important, a lot of visitors riding the train back to Anchorage after a 16-hour marathon to Kenai Fjords are so tired they can't keep their eyes open for the extraordinary scenery passing by. A better plan is to spend at least 1 night in Seward and take in the full Kenai Fjords boat trip and Exit Glacier.
Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.