Oil pressure pegged

[Dave Rifkin]

Yesterday I took my 1969 Corvette out on a Marine's sponsored Toys 4 Tots run. Had the car up to 85 ish on the highway, running great. Had to deal with a lot of traffic getting into the event, which did not make the car very happy. Temp gauge got to 210 and she felt like it was loading up; possibly the beginnings of vapor lock.

Anyway, the ride home was uneventful but, this morning when I went to take it out for another ride I noticed that the oil pressure gauge was pegged. I was only heading down my street, maybe 15 mph. When I let off the gas and let it idle the needle sat between 35 and 70.
Normally the gauge reads 35 when I am driving and never gets anywhere near 70. I immediately brought it home. I checked the oil, it's full and clean.

Any ideas what the cause could be and/or what I should do?