For one of the longest and most scenic hikes in Chugach State Park [1], head out on the 25-mile Crow Pass Trail. This trail (also known as the Historic Iditarod Trail) provided a turn-of-the-20th-century overland route from Seward [2] through the Chugach to the Interior [3] gold mining town of Iditarod.
The gradual climb to Crow Pass fords several streams, including Eagle River midway along the trail. It might be wise to camp overnight and cross the river in the morning, when the glacial runoff is lower.
Raven Glacier and Crystal Lake are scenic highlights near Crow Pass, where you leave Chugach State Park and continue in immense Chugach National Forest [4].
The Forest Service has a popular A-frame cabin (518/885-3639 or 877/444-6777, www.recreation.gov [5], $35) on the summit that you can rent. From the cabin it’s four miles down to the trailhead on rough Crow Creek Road, then another five miles to the Alyeska Ski Resort [6] access road.
Experienced skiers sometimes use the Iditarod and Crow Pass Trails for a winter traverse of the mountains, but be aware that avalanche danger can be very high.
Links:
[1] http://www.moon.com/destinations/alaska/anchorage/excursions-anchorage/chugach-state-park
[2] http://www.moon.com/destinations/alaska/kenai-peninsula/seward
[3] http://www.moon.com/destinations/alaska/the-interior
[4] http://www.moon.com/destinations/alaska/kenai-peninsula/eastern-kenai-peninsula/chugach-national-forest
[5] http://www.recreation.gov
[6] http://www.moon.com/destinations/alaska/anchorage/excursions-anchorage/girdwood/recreation