Complex sentence: By today's standards, all construction was done by hand and the equipment used in the construction was quite primitive, but the construction of Bagnell Dam was completed and Lake of the Ozarks was at full reservoir in less than two years.
Split into simpler sentences: By today's standards, all construction was done by hand, and the equipment used in the construction was quite primitive. The construction of Bagnell Dam was completed and Lake of the Ozarks was a full reservoir in fewer than two years.