Emigration to the West decreased over the following years, but it is likely that the drop in numbers was caused more by fears over the outcome of the ongoing Mexican–American War than by the cautionary tale of the Donner Party. In 1846, an estimated 1,500 people migrated to California. In 1847, the number dropped to 450 and then to 400 in 1848. The California Gold Rush spurred a sharp increase, however, and 25,000 people went west in 1849. Most of the overland migration followed the Carson River, but a few forty-niners used the same route as the Donner Party and recorded descriptions about the site.