"Suicune is seen in the following places and you must follow it if you wish to capture it. First, it will be found in the north of Cianwood City. After you encounter it there, you will shortly find it outside the entrance of Mt. Mortar in Route 42. Once you find it here, it will leave Johto and head to Kanto where you will see it in Vermillion City soon after you arrive. Next you will see it in Route 14 where it will escape for the final time to be found outside Bill's House in Route 25 after Misty has returned to her gym. This is where you battle Suicune."
THAT'S MISS HOME ROWED TO YOU http://i50.tinypic.com/kcb3t4.jpg
It goes Burned Tower - Cianwood City - Route 42 then I believe it skips to Kanto and starts in Vermilion City - Route 14 - then Route 25 near Bill's house and after Misty returns to her gym or something