Lock and Dam 1 were built from 1836-1842 and support a 27-mile long pool of water. The original dam was a timber crib structure, consisting of an outside frame of timbers filled with dirt and rock, and the original lock was stone masonry. The structures are located four miles above the mouth of the Ohio River. Lock 1 was shut down in 2007 because of mechanical and structural problems.
1836-1842 Original construction of lock and dam
1882 Dam is rebuilt by the Corps of Engineers
1902-1908 Concrete cap is added to the top of the timber crib dam
1953 New upper miter sill is added in the lock chamber, Upper gates are upgraded from wood to steel
1955 Lower lock gates are upgraded from wood to steel
1977-1978 New concrete is added to crest of the dam, Surface repairs are made to cracks in the existing concrete cap on the dam, Sheet pilling is added to front of dam
1991 New lower lock gates are added
Some further history, photos, and news articles from various years can be found here.