Starting in 2014, Zimmerman Lake has been stocked annually with 900 to 1,000 age-1 Greenback Cutthroat Trout (Bear Creek). The population represents an important brood source, meaning that eggs are collected and fertilized annually to support stocking in other recovery projects, and to perpetuate the Zimmerman and Leadville National Fish Hatchery broodstocks. Prior to stocking the first-year class of Bear Creek Greenbacks in 2014, Colorado Parks and Wildlife (CPW) and US Fish and Wildlife established an agreement that CPW would monitor catch and release angling, to protect CPW’s ability to manage the population for catch and release fishing. Thus, a creel study began in 2015 to measure angling use at Zimmerman Lake. The Creel Study utilizes a combination of creel cards and a motion detecting creel camera to quantify angling use. The creel cards are a voluntary questionnaire to evaluate angling effort, catch, and other human dimension parameters. The creel camera provides an estimate of the actual number of anglers that visit Zimmerman in a season, which also enables the ability to estimate participation in the creel card survey. The camera captures a coarse image of everyone who hikes to the lake, providing a date and time stamp for each image. CPW technicians then sort through all the images to determine how many visitors were anglers, and when they arrived and left. This combined approach enables an annual evaluation of trends in angling pressure and catch. Rocky Mountain Flycasters Volunteers are assisting with the creel card survey portion of the creel study at Zimmerman Lake. Our primary responsibility is to keep new cards stocked at the kiosk and retrieve and collect completed cards. This volunteer effort begins as ice comes off the lake (mid-June) and runs through the fall. To maintain the study, the kiosk needs to be serviced monthly.