In the 1890s , his publication rate increased to an average of 43 articles a year . His final expedition to the West took place in 1894 , when he prospected for dinosaurs in South Dakota and visited sites in Texas and Oklahoma .
In the 1890s his publication rate increased to an average of 43 articles a year.p350 His final expedition to the West took place in 1894 , when he prospected for dinosaurs in South Dakota and visited sights in Texas and Oklahoma .