Did the gauge actually show it over heating?

On long trips where you work the engine fairly hard like that,
when you pull up and stop, sometimes the coolant gets a flash
of heat and now the engine is pumping it through the radiator,
it will boil out the over-flow. Doesn't mean anything is wrong.

After a long hard trip, you should always let the engine idle for a minute or two to help get the heat out of it.
That will help prevent it from boiling out the over-flow.

It doesn't necessarily mean anything is wrong.

1995 Trooper LS auto 3.2 DOHC /w SOHC intake
1989 Trooper 2.6 auto
1989 I-Mark RS DOHC 1.6
1991 Stylus XS DOHC 1.8