Volunteer Naturalists lead walks in Lower Sabino Canyon every Monday through Thursday, through Thursday, April 26; free. Parking is $5 per day or $20 per year. Children younger than 18 must be accompanied by an adult. Monday, 2 to 4 p.m.: Secrets of Sabino Revealed. Tuesday, 8:30 to 11:30 a.m.: plant and bird walk with photography tips. Wednesday, 8:30 to 11:30 a.m.: nature walk with photography tips for insects and rock formations. Thursday, 8:30 to 11 a.m.: Gneiss Walk, a 2.5 hour walk looking at geology. Call or visit scvntucson.org
for more information.