Historical Price Data – Splits

I’m looking at a historical price table in Yahoo Finance, and wondering how splits are accounted for in price.

As an example I’m looking at DIS for the period 7/1/98 – 7/31/98.

There was a 3:1 stock split on 7/10/98, but I don’t see the price having been adjusted from that split.

7/9/98 – $36.50
7/10/98 – $37.61

My question is, when splits happen – are all historical prices in the table adjusted for that corporate action event?

I’m trying to figure out my cost basis for shares that my grandmother bought me, but I don’t have the original transaction info. All I have is Trade Date and shares purchased. So to get the price and net amount I’m needing to lookup the prices.

Just wanting to understand if the prices in the Yahoo Finance historical table are accurate, or maybe someone knows of a better source for historical price data.

Thanks a bunch