In the Northern states walleye spawn from April to May. They usually start when the water temperature gets around 40 degrees and the spawn usually ends around 52 degrees Fahrenheit. They usually spawn on the North East shorelines up north because that's where the sun tends to hit during midday and it's warmest there. Even if there is ice on the lake they can still spawn because there's no ice there.
You're in Colorado so it's a bit different even though you guys ice over too. I think Walleye typically start their spawn there around the same time and temperature but the spawn can go a little bit warmer there.
In Oklahoma it's a little bit different, as we have more saugeye here than walleye and they are a little more tolerant of the warmer temperatures.
Typically walleye will spawn on gravel beds or sandy flats. They need their eggs to settle in a little bit to protect them from other predators. That's why they like the gravel and rocks to spawn. If you can find a fairly shallow water up to about 12 feet.
Usually, if you are fishing for walleye in early spring and you can get a day with a little broken up cloud cover and a little bit of a breeze, you can have a pretty good day. The clouds and the waves from the breeze break up the light and it stimulates them to feed because they have an advantage in sight during these conditions.
Use your depth finder and when you locate the fish, drift through them using a wind sock and circle back around.
Okay, you didn't ask for all that, sorry. You just got me fired up about catching some walleye this spring. I can't wait. Gonna fire up the boat and head down to Ft. Cobb lake as soon as I can! I'm starting to get hooked on walleye fishing like I used to be with largemouth bass fishing as a kid. And damn they taste good!