Agate created the first known picture of Mount Shasta. Agate contributed more than half (173 of 342) of the sketches and paintings reproduced as lithographs illustrating the five volumes of the expedition's reports. He sketched the Oregon Territory, including a look into a Chinook Lodge, an Indian Burial Place, an Indian Mode of Rocking Cradle, and a picture of the wreck of one of the expedition's sailing ships at the mouth of the Columbia River.