We got lost immediately outside Blaine. This bike ride seemed to be going nowhere fast, and it was all my fault.

Fortunately, I was not on a bike. I was sitting in my truck, the air conditioner and radio on and a strong cuppa in the holder.

But my sister and her friend? They pedaled away on this hot day last August, unable to make sense of my route sheets and getting conflicting advice from their two Garmins, even though the GPS devices had been loaded with identical maps.

This was the start of a bike ride (ultimately successful) from the Canadian to the Mexican border, and my job was SAG — support and gear/guidance — across Washington state. It's the important job that cycling outfitters or bike clubs provide when you pay for guided bike tours or sign up for long-distance group rides.

I had intended to be on my bike for this adventure, but my body missed a post-surgery email with the recuperation schedule and hadn't shown up for training rides. Now I was just happy to be here in a supporting role.

Too bad I was so lousy at it. Let this be a lesson to the uninitiated: SAGing's not as easy as it sounds.

Map challenges

My wife, in the truck cab with me, was trying to follow the route I had mapped across the state. But it looked like getting out of Whatcom County might be an insurmountable challenge if we stuck to my cartography. We crisscrossed the area south of Blaine for an hour or two, finally abandoned our charges in favor of a fragrance garden at Lake Tennant near Ferndale. We were having a lovely time when our riders called to say they had arrived in Bellingham, the day's destination, no thanks to us.

Things didn't go much better the next day. With my wife safely back in Seattle, I went solo, trying to follow the route north as my riders rode south, expecting to meet them halfway. But once again, my maps were flawed. Roads I thought would go straight to Mount Vernon went straight to ... nowhere.

I rode around Skagit and Whatcom counties listening to an audio book of Bill Bryson's frustrations with British public transportation and his futile efforts to find his way around a small island. This left me lost between a vicarious unsuccessful search for Tintern Abbey and a very real inability to find my way off Bow Hill Road. I wandered lonely as a clod, a sad sack of a SAG. Sis and friend had to find their way into Mount Vernon on their own.

The third day was a charm. I steered them to the Centennial Trail in Bryant and met them at the other end in Snohomish. A couple nice things about a bike trail: It's hard to get lost and it gets riders safely away from traffic. But it also separates them from their SAG. If they'd had a flat or some other problem, I couldn't park beside them in my truck and deliver a new tube and a pump. Essentially this renders the SAG person useless — or in my case, worse than useless.

By Day 4, I was getting the hang of it. It helped that we were following someone else's map, the Seattle-to-Portland Ride guide. But even though 10,000 riders had come this way only a few weeks before, there were problems — and opportunities for me to be helpful: coming up with detours around unmarked road-construction projects, waving at turns that would have been easy to miss, scouting out lunch stops.

Bridge panic

I began to relax a bit, even started thinking I could protect my riders from anything — a notion that blew apart on Day 6 on the Lewis and Clark Bridge that crosses the Columbia River at Longview.

My plan had been to follow the bicyclists in my truck, emergency lights flashing, keeping bigger vehicles from running over them. But at the first blast from a semi's air horn, I freaked, veered left, shot past the pedalers and noted with horror that the "bike lane" was littered with bark and other debris from logging trucks. How could a bike rider get through that mess? Somehow, my two did.

The bridge made me realize I couldn't protect riders from everything. I couldn't pull out my broom and clear the littered bike lane for them. I couldn't keep jerks in Mount Vernon from yelling obscenities at them. I couldn't be there when each speeding car passed them on a highway — perhaps too close for comfort. I could do as much as possible, but in the end, safety mostly depended on their alertness, and that of drivers around them.

Comforts count

If I could not guarantee 100 percent safety, I could do better on what I saw as my second most important responsibility: Keep them happy. There, I could carry their luggage, give them treats and cold water and find a decent evening meal and place to stay.

I think I succeeded there, and I know one thing for sure: I was one happy SAG by the end of the trip. It was a great excuse to tool around the state on two-lane blacktops and to spend time with my sister and get to know her friend better. My lawn chair and book were perfect for lounging on the side of the road or in a park waiting for the riders to come shooting off a bike trail or go flying by on the highway. It's obviously not a prospective career for me, but it's an enjoyable thing to do for a sister, a friend and yourself.

John B. Saul, a former Seattle Times editor, is a freelance writer and occasional bike rider.