- You can only have one active bounty at a time.
- You can post multiple bounties to one question, sequentially.
- Post bounty to a specific question
- Award that bounty
- Post another bounty to that same question
- Visit your active bounties tab ( https://stackoverflow.com/users/2915/adam-davis?tab=bounties#bpage_1-bsort_active in my case, and is exhibit 1, also captured in a screenshot below since it won't appear this way once I award the bounty)
Note that you have 2 active bounties - the one which really is active, and the one you previously awarded and is not active. The screenshot below demonstrates this for 1 active bounty and 4 prior awarded bounties posted on the same question.