The link you supplied Dallas wants you to sign up.
Try this link instead to find the ones listed in yours on a map.

I've done the Leon Creek one from the Ingram Via Park n Ride to 1604/10 (before they had it completed that far.)
Also the Mission one from downtown to below 410 south and back with a Provider friend. If you do it during sunny weather, bring sun screen since not much shade.

Been wanting to do the one by Starcrest/410 (Tobin trail?) for the longest time.