In addition to Maggie's excellent suggestion about checking the OKGenWeb site for Maps N More and the Township Grid link, I would add a suggestion. I have found that this link, which leads you to an interactive map of Oklahoma Counties, does not yet have all the links updated. For example, if you click on Carter County on this map you will go to a site which has a message that the information is still under construction. In fact, the township grid data is available, but you have to access it from another link.
When you access the Maps N More site on OKGenWeb, scroll down the page to All County Links, and enter it. Select the county of interest and then click on the Township link in the section of the page labeled Oklahoma Department of Transportation Maps. This will take you to a grid of all the townships and ranges within that county. In addition, you could also click on the link entitled Town Links from the All County Links page and be able to see most Oklahoma towns within that particular county and where they are located on the township map.
Also, a good website to access if you would like to get a tutorial on legal land descriptions is Vikki Gray's site located at: http://www.ghostseekers.com/Landtutorial.htm
There is also a link on the OKGenWeb Maps N More site which addresses Land Descriptions for Oklahoma.