Complex sentence: In 1908 President Theodore Roosevelt created Pinnacles National Monument with the power given him in the Antiquities Act of 1906 to commemorate the people and organizations instrumental to the creation and early protection of the park.
Split into simpler sentences: In 1908 President Theodore Roosevelt created Pinnacles National Monument with the power given him in the Antiquities Act of 1906. To commemorate the people and organizations instrumental to the creation and early protection of the park.