Button Rock Reservoir, located 7 miles west of Lyons, Colorado, is a protected drinking water supply reservoir where recreational paddling is prohibited. The reservoir and surrounding Button Rock Preserve are managed by the City of Longmont primarily to protect municipal water resources.

The 2,671-acre preserve contains both Ralph Price Reservoir (Button Rock) and Longmont Reservoir along the North Saint Vrain Creek. A city ordinance explicitly prohibits watercraft activity within the preserve, with one narrow exception - kayakers may pass through when entering from Upper North St. Vrain Creek upstream of Button Rock Dam, but must continuously move downstream without stopping.

The reservoir sits in a quiet river valley surrounded by diverse wildlife habitat. Visitors frequently observe eagles, osprey, great blue herons, and various waterfowl around the water. The surrounding preserve features steep canyon walls and forested slopes rising to nearly 7,500 feet elevation.

Access requires a two-mile hike from the main parking area, as vehicle access is restricted beyond the entrance gate. The preserve is open daily from 3:00 AM to 10:00 PM, though overnight parking is prohibited. Water temperatures can be quite cold even in summer, with readings as low as 53 degrees Fahrenheit reported.

While paddling is not permitted, the reservoir supports a managed fishing program from May through October (special permit required). The 2013 flood caused significant damage to the area, but restoration work has been completed on both the dam infrastructure and surrounding riparian zones.

Given its role as a critical municipal water supply and nature preserve, recreational paddling opportunities are not available at Button Rock Reservoir. Paddlers should seek alternative locations for water recreation.