CPKC, formed through the merger of Canadian Pacific and Kansas City Southern, has created a seamless north-south corridor linking Canada, the central U.S., and Mexico. This unified network supports aggregate shipments from resource-rich regions in Canada and the Midwest into high-growth markets in Texas and Mexico. In Texas, parts of the network rely on leased rail to connect key segments, ensuring access to critical industrial and construction hubs. While its overall footprint is smaller than the major U.S. railroads, CPKC's strategic focus on cross-border markets makes it a critical player in the aggregate supply chain. CN connects Canadian aggregate sources to the central and southern United States, leveraging its access to the Midwest, Mississippi River, and Gulf Coast ports. This positions CN as an important conduit for industrial and export-oriented aggregate shipments, though its limited U.S. reach makes it more of a specialized carrier than a dominant player.