If you hear a fisher speaking of their life list, they aren't talking about the lifelong to do list from their better half.

Rather, they're speaking of the number of fish species they have caught over a lifetime of fishing. For some, the list is short. For others, it approaches the length of a child's wish list around Christmas. Some fishers could care less about their life list, often focusing on a relatively few species such as trout. For others, it's an obsession. Sounds like someone I saw in the mirror this morning.

While it might be argued that there is only one true life list, there are many variations on the theme. They run the gamut from everything caught in any manner anywhere in the world to very specific lists such as the number of species caught in Colorado on a fly.

One that I'm currently working on is to catch a Master Angler-sized fish on a fly for every species on the Colorado Division of Wildlife's list (http://wildlife.state.co.us/Fishing). While that may seem like a short list, the DOW currently recognizes 43 species. I've only got Master Angler awards for 13 of them.

Thanks in large part to the DOW, there is great diversity in the state's fisheries. Actually, there are a lot more fish species than those on the Master Angler list, as it doesn't even fully account for all the known game species in Colorado.

Appropriately, none of the 15 endangered/threatened species are on the list and most of the non-game species such as shiners, chubs, sculpins and shad are not listed.

That means the number of fish species in Colorado is likely more than 100. Now that's a life list.

For the truly adventuresome fisher, there are even greater lists with some 700 fresh water species in the U.S. Include saltwater and go worldwide and you're looking at more than 20,000 varieties.

At one per day, 365 days a year, that means I need a good 50 years to catch them all. Alright, some may not be catchable with a line and reel, let alone a fly, but it still seems to be a worthy endeavor.

Why bother with a life list? That's a lot like asking, "Why climb Colorado's fourteeners?"

The simple answer is, for the challenge. When you fish for everything that swims, it pushes the limits of your skills and makes you a better fisher. Plus, there are the bragging rights.

It's great fun when sitting at the table with fellow fishers swapping lies, err, tales to ask, "Yes, but, what is the biggest catfish you've caught fly fishing?"

While many of Colorado's fish are not viewed with high regard, each offers its own set of challenges, especially to a fly fisher. So, if you're looking to push your fishing skills, consider building up your life list.