How is the State Plane Coordinate system set up? Can GPS provide coordinates in these values? What about Public Land Survey System (PLSS) readouts?

The State Plane Coordinate System (SPCS) is a plane coordinate system (N-S and E-W lines are perpendicular) in which each individual state has from one to six zones, depending on the state's size and shape. The grid system in some states is based on the Lambert Conformal Conic Projection, while the system for other states is based on the Transverse Mercator Projection. As a general rule-of-thumb, states that are longer E-W than N-S use Lambert, while states that are longer N-S use Transverse Mercator. The most notable exception to this is California, which is based on Lambert.

Most USGS 7.5-minute historical maps (circa 1947-1995) show NAD27 SPCS grid ticks along the map projection line. The zone is given in the credit note, and coordinate values are annotated at one or more corners. However, these NAD27 coordinates have almost no value today. 

When SPCS NAD83 was defined, parameters were selected that would make the coordinate values noticeably different from the NAD27 values. From 2010 to 2016 the US Topo project continued the historic 7.5-minute SPCS annotation conventions using NAD83 SPCS values, but SPCS ticks and annotation were dropped from these maps in 2017.

Most Geographic Information Systems (GIS) can display SPCS values and grids, and some consumer GPS devices and apps also implement SPCS. However, SPCS is important today mostly for land surveying and specialized local mapping.

The Public Land Survey System (PLSS) is a different type of system. It is not a geographic grid system, is not calculable from geographic coordinates, and therefore is not supported by GPS technology. See this FAQ for information about PLSS on USGS maps.