SPOILER][/SPOILER]I think Andy was thinking of the place before he escaped, as it seemed to hold fond memories for him. I think he would have had to stop by there after he cashed out all the accounts after he escaped and left the money and letter for Red to find later, since he had no idea when Red would actually get out of prison. It looks like the tin box had been there for a while under the rocks when Red finds it, so although I don't think the movie actually says how long it is after Andy escapes that Red gets paroled, it seems that it may have been a few more months or even years. Ms. Mod, or Flake, either I'm not using the spoiler function correctly or it is not working on this end. I'm thinking the former is more likely than the latter. Sorry about this.