A Pacific Northwest Open-Air Event Venue in Castle Rock, WA

Tucked into the towering evergreens of southwest Washington, Alder Grove is a private open-air event venue located three miles west of Castle Rock, WA — the official Gateway to Mount St. Helens. Set on the former historic Crosby family tree farm at 445 Growlers Gulch Road, just off PH10 (Postal Highway 10), Alder Grove was built for moments that deserve more than four walls: fairytale outdoor weddings beneath a canopy of native alders and Douglas firs, corporate retreats, family reunions, and live outdoor concerts framed by sweeping views of Mt. Rainier from the ceremony grounds, with Mt. St. Helens rising to the east.

The location is uniquely accessible. Castle Rock sits directly off Interstate 5 in Cowlitz County, roughly 60 miles north of Portland, Oregon and just over 100 miles south of Seattle — putting Alder Grove within easy reach for couples and corporate groups from both metro areas without sacrificing the privacy and natural character of a true Pacific Northwest forest setting. The grounds blend professionally landscaped gardens with wild forest character: manicured lawn space for ceremonies and seated dinners flows naturally into wooded trails, water features, and quiet clearings perfect for portraits, golden-hour photography, and intimate conversation.

As a fully permitted commercial event center, Alder Grove is purpose-built for hosting. On-site amenities include private bridal quarters, a dedicated catering building, on-premise lavatories, and ample parking — all on grounds patrolled by on-site security so your celebration stays private and uninterrupted. Catering and bar services are coordinated through our hand-selected roster of local southwest Washington and Portland-area vendors, and our team works alongside you to ensure every detail — from setup to cleanup — is handled with care.