He runs the site Modern Hiker, where he writes trail guides on various hiking routes in Southern California.
[3] The blog began to pick up attention as he posted more articles and guides about Los Angeles-area trails.
Schreiner has become somewhat of a public figure in the outdoors community, covering both local and national issues.
Schreiner is a frequent guest commentator on outdoor issues in Southern California,[7] and is the author of "Day Hiking Los Angeles," a 348-page hiking guidebook published by Mountaineers Books in late 2016.
It is the first ever in-depth guidebook for Griffith Park and reached the Los Angeles Times' bestseller list.