[Inyo-Mono]

One of the main differences is that the historical USGS 7.5-minute topographic map series (produced 1945-1992) included feature classes that are not yet shown on US Topo maps (though more are added each year). Examples include recreational trails, pipelines, power lines, survey markers, many types of boundaries, and many types of buildings.

Which makes the older paper maps more valuable if you hike or use the maps for off-roading.

[GingisK]

Yeah, the old ones also had labels on ore deposits and mines.

[Jarvis Law 2.0]

I love those maps, used to work with them a lot as base maps for other things. Another great feature found on the USGS topo sheets (going from my very old memory) is the magnetic north arrow compared with with True North arrow and how much deviation there has been over the years... comes in handy when using a compass & the GPS goes wonky.

[Retain Mike]

The absence of survey markers is unacceptable.