COVID-19: Restrictions on Travelers at U.S. Land Borders [Updated April 23, 2020] [open pdf - 543KB]
From the Document: "New actions by the federal government in response to the COVID-19 [coronavirus disease 2019] pandemic restrict the entry of certain foreign nationals into the United States. Customs and Border Protection (CBP), within the Department of Homeland Security (DHS), and the Centers for Disease Control and Prevention (CDC), within the Department of Health and Human Services (HHS), have recently issued orders regarding travelers arriving at land ports of entry (POEs) at both the northern and southern borders of the United States."
CRS Insight, IN11308
Congressional Research Service: https://crsreports.congress.gov/