Typically, sea-run cutthroat first enter salt water in the spring at an age of two years and a length of 6 to 8 inches. In the late summer and fall they return to fresh water for the first time at a length of 10-12 inches (many will not spawn on their first return). Every year thereafter they repeat the cycle; spending the late spring and summer in salt water and returning to the river to spawn. It's difficult to give any more accurate parameters because sea-run cutthroat exhibit more varied life histories than almost any other salmonid. Some may enter the rivers as early as July and some as late as February; spawning may take place at any time from February until June (the peak spawning month being, in most rivers, March). A 20-inch sea-run cutthroat will probably be 9 or 10 years old. The oldest recorded sea-run cutthroat was a 12 year old from one of Oregon's coastal rivers.