If I put the Between clause in quotes, it tries to interpret it as a literal. Do you know exactly how to code a between in the decode? I can't find any literature on it specifically.

SELECT
DECODE(UPPER(SUBSTR(ACTIVITY_ID,2,1))
,'1','Water'
,BETWEEN 'A' and 'Z','Water'
,'2','Waste'
,'3','ToolA/ToolB'
,'5','Shared'
,'Unknown'
) fund
,activity_id
from
SCHEMA.TABLE_INFO
where table_id like 'C%'